Data Acquisition

Downloaded three GEO files: 1. Expression matrix (series_matrix) 2. Metadata (SOFT via GEOquery)

32,049 genes measured across 388 samples

data <- read.table("GSE63061_series_matrix.txt",
                   header = TRUE,
                   sep = "\t",
                   comment.char = "!",
                   check.names = FALSE)

dim(data)
## [1] 32049   389
head(data[,1:5])
##         ID_REF GSM1539409 GSM1539410 GSM1539411 GSM1539412
## 1 ILMN_1343291  12.552807  12.711459  13.088393  12.643831
## 2 ILMN_1343295  10.101556   9.776015   9.594397  10.126782
## 3 ILMN_1651209   6.084671   6.255012   6.160485   6.109219
## 4 ILMN_1651210   6.068805   6.016468   6.024322   6.016118
## 5 ILMN_1651221   6.121060   6.173167   6.039552   6.111306
## 6 ILMN_1651228  10.833984  10.270673  10.430594  10.765207
data <- as.matrix(data)
mode(data) <- "numeric"
## Warning in mde(x): NAs introduced by coercion
data <- na.omit(data)

summary(data)
##      ID_REF      GSM1539409    GSM1539410    GSM1539411    GSM1539412 
##  Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA  
##  1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA  
##  Median : NA   Median : NA   Median : NA   Median : NA   Median : NA  
##  Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN  
##  3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA  
##  Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA  
##    GSM1539413    GSM1539414    GSM1539415    GSM1539416    GSM1539417 
##  Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA  
##  1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA  
##  Median : NA   Median : NA   Median : NA   Median : NA   Median : NA  
##  Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN  
##  3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA  
##  Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA  
##    GSM1539418    GSM1539419    GSM1539420    GSM1539421    GSM1539422 
##  Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA  
##  1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA  
##  Median : NA   Median : NA   Median : NA   Median : NA   Median : NA  
##  Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN  
##  3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA  
##  Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA  
##    GSM1539423    GSM1539424    GSM1539425    GSM1539426    GSM1539427 
##  Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA  
##  1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA  
##  Median : NA   Median : NA   Median : NA   Median : NA   Median : NA  
##  Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN  
##  3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA  
##  Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA  
##    GSM1539428    GSM1539429    GSM1539430    GSM1539431    GSM1539432 
##  Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA  
##  1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA  
##  Median : NA   Median : NA   Median : NA   Median : NA   Median : NA  
##  Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN  
##  3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA  
##  Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA  
##    GSM1539433    GSM1539434    GSM1539435    GSM1539436    GSM1539437 
##  Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA  
##  1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA  
##  Median : NA   Median : NA   Median : NA   Median : NA   Median : NA  
##  Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN  
##  3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA  
##  Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA  
##    GSM1539438    GSM1539439    GSM1539440    GSM1539441    GSM1539442 
##  Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA  
##  1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA  
##  Median : NA   Median : NA   Median : NA   Median : NA   Median : NA  
##  Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN  
##  3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA  
##  Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA  
##    GSM1539443    GSM1539444    GSM1539445    GSM1539446    GSM1539447 
##  Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA  
##  1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA  
##  Median : NA   Median : NA   Median : NA   Median : NA   Median : NA  
##  Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN  
##  3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA  
##  Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA  
##    GSM1539448    GSM1539449    GSM1539450    GSM1539451    GSM1539452 
##  Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA  
##  1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA  
##  Median : NA   Median : NA   Median : NA   Median : NA   Median : NA  
##  Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN  
##  3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA  
##  Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA  
##    GSM1539453    GSM1539454    GSM1539455    GSM1539456    GSM1539457 
##  Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA  
##  1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA  
##  Median : NA   Median : NA   Median : NA   Median : NA   Median : NA  
##  Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN  
##  3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA  
##  Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA  
##    GSM1539458    GSM1539459    GSM1539460    GSM1539461    GSM1539462 
##  Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA  
##  1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA  
##  Median : NA   Median : NA   Median : NA   Median : NA   Median : NA  
##  Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN  
##  3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA  
##  Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA  
##    GSM1539463    GSM1539464    GSM1539465    GSM1539466    GSM1539467 
##  Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA  
##  1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA  
##  Median : NA   Median : NA   Median : NA   Median : NA   Median : NA  
##  Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN  
##  3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA  
##  Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA  
##    GSM1539468    GSM1539469    GSM1539470    GSM1539471    GSM1539472 
##  Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA  
##  1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA  
##  Median : NA   Median : NA   Median : NA   Median : NA   Median : NA  
##  Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN  
##  3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA  
##  Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA  
##    GSM1539473    GSM1539474    GSM1539475    GSM1539476    GSM1539477 
##  Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA  
##  1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA  
##  Median : NA   Median : NA   Median : NA   Median : NA   Median : NA  
##  Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN  
##  3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA  
##  Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA  
##    GSM1539478    GSM1539479    GSM1539480    GSM1539481    GSM1539482 
##  Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA  
##  1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA  
##  Median : NA   Median : NA   Median : NA   Median : NA   Median : NA  
##  Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN  
##  3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA  
##  Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA  
##    GSM1539483    GSM1539484    GSM1539485    GSM1539486    GSM1539487 
##  Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA  
##  1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA  
##  Median : NA   Median : NA   Median : NA   Median : NA   Median : NA  
##  Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN  
##  3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA  
##  Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA  
##    GSM1539488    GSM1539489    GSM1539490    GSM1539491    GSM1539492 
##  Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA  
##  1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA  
##  Median : NA   Median : NA   Median : NA   Median : NA   Median : NA  
##  Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN  
##  3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA  
##  Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA  
##    GSM1539493    GSM1539494    GSM1539495    GSM1539496    GSM1539497 
##  Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA  
##  1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA  
##  Median : NA   Median : NA   Median : NA   Median : NA   Median : NA  
##  Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN  
##  3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA  
##  Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA  
##    GSM1539498    GSM1539499    GSM1539500    GSM1539501    GSM1539502 
##  Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA  
##  1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA  
##  Median : NA   Median : NA   Median : NA   Median : NA   Median : NA  
##  Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN  
##  3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA  
##  Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA  
##    GSM1539503    GSM1539504    GSM1539505    GSM1539506    GSM1539507 
##  Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA  
##  1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA  
##  Median : NA   Median : NA   Median : NA   Median : NA   Median : NA  
##  Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN  
##  3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA  
##  Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA  
##    GSM1539508    GSM1539509    GSM1539510    GSM1539511    GSM1539512 
##  Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA  
##  1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA  
##  Median : NA   Median : NA   Median : NA   Median : NA   Median : NA  
##  Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN  
##  3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA  
##  Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA  
##    GSM1539513    GSM1539514    GSM1539515    GSM1539516    GSM1539517 
##  Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA  
##  1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA  
##  Median : NA   Median : NA   Median : NA   Median : NA   Median : NA  
##  Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN  
##  3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA  
##  Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA  
##    GSM1539518    GSM1539519    GSM1539520    GSM1539521    GSM1539522 
##  Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA  
##  1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA  
##  Median : NA   Median : NA   Median : NA   Median : NA   Median : NA  
##  Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN  
##  3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA  
##  Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA  
##    GSM1539523    GSM1539524    GSM1539525    GSM1539526    GSM1539527 
##  Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA  
##  1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA  
##  Median : NA   Median : NA   Median : NA   Median : NA   Median : NA  
##  Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN  
##  3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA  
##  Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA  
##    GSM1539528    GSM1539529    GSM1539530    GSM1539531    GSM1539532 
##  Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA  
##  1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA  
##  Median : NA   Median : NA   Median : NA   Median : NA   Median : NA  
##  Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN  
##  3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA  
##  Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA  
##    GSM1539533    GSM1539534    GSM1539535    GSM1539536    GSM1539537 
##  Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA  
##  1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA  
##  Median : NA   Median : NA   Median : NA   Median : NA   Median : NA  
##  Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN  
##  3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA  
##  Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA  
##    GSM1539538    GSM1539539    GSM1539540    GSM1539541    GSM1539542 
##  Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA  
##  1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA  
##  Median : NA   Median : NA   Median : NA   Median : NA   Median : NA  
##  Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN  
##  3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA  
##  Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA  
##    GSM1539543    GSM1539544    GSM1539545    GSM1539546    GSM1539547 
##  Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA  
##  1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA  
##  Median : NA   Median : NA   Median : NA   Median : NA   Median : NA  
##  Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN  
##  3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA  
##  Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA  
##    GSM1539548    GSM1539549    GSM1539550    GSM1539551    GSM1539552 
##  Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA  
##  1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA  
##  Median : NA   Median : NA   Median : NA   Median : NA   Median : NA  
##  Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN  
##  3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA  
##  Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA  
##    GSM1539553    GSM1539554    GSM1539555    GSM1539556    GSM1539557 
##  Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA  
##  1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA  
##  Median : NA   Median : NA   Median : NA   Median : NA   Median : NA  
##  Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN  
##  3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA  
##  Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA  
##    GSM1539558    GSM1539559    GSM1539560    GSM1539561    GSM1539562 
##  Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA  
##  1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA  
##  Median : NA   Median : NA   Median : NA   Median : NA   Median : NA  
##  Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN  
##  3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA  
##  Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA  
##    GSM1539563    GSM1539564    GSM1539565    GSM1539566    GSM1539567 
##  Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA  
##  1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA  
##  Median : NA   Median : NA   Median : NA   Median : NA   Median : NA  
##  Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN  
##  3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA  
##  Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA  
##    GSM1539568    GSM1539569    GSM1539570    GSM1539571    GSM1539572 
##  Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA  
##  1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA  
##  Median : NA   Median : NA   Median : NA   Median : NA   Median : NA  
##  Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN  
##  3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA  
##  Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA  
##    GSM1539573    GSM1539574    GSM1539575    GSM1539576    GSM1539577 
##  Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA  
##  1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA  
##  Median : NA   Median : NA   Median : NA   Median : NA   Median : NA  
##  Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN  
##  3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA  
##  Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA  
##    GSM1539578    GSM1539579    GSM1539580    GSM1539581    GSM1539582 
##  Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA  
##  1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA  
##  Median : NA   Median : NA   Median : NA   Median : NA   Median : NA  
##  Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN  
##  3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA  
##  Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA  
##    GSM1539583    GSM1539584    GSM1539585    GSM1539586    GSM1539587 
##  Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA  
##  1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA  
##  Median : NA   Median : NA   Median : NA   Median : NA   Median : NA  
##  Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN  
##  3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA  
##  Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA  
##    GSM1539588    GSM1539589    GSM1539590    GSM1539591    GSM1539592 
##  Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA  
##  1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA  
##  Median : NA   Median : NA   Median : NA   Median : NA   Median : NA  
##  Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN  
##  3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA  
##  Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA  
##    GSM1539593    GSM1539594    GSM1539595    GSM1539596    GSM1539597 
##  Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA  
##  1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA  
##  Median : NA   Median : NA   Median : NA   Median : NA   Median : NA  
##  Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN  
##  3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA  
##  Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA  
##    GSM1539598    GSM1539599    GSM1539600    GSM1539601    GSM1539602 
##  Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA  
##  1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA  
##  Median : NA   Median : NA   Median : NA   Median : NA   Median : NA  
##  Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN  
##  3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA  
##  Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA  
##    GSM1539603    GSM1539604    GSM1539605    GSM1539606    GSM1539607 
##  Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA  
##  1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA  
##  Median : NA   Median : NA   Median : NA   Median : NA   Median : NA  
##  Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN  
##  3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA  
##  Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA  
##    GSM1539608    GSM1539609    GSM1539610    GSM1539611    GSM1539612 
##  Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA  
##  1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA  
##  Median : NA   Median : NA   Median : NA   Median : NA   Median : NA  
##  Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN  
##  3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA  
##  Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA  
##    GSM1539613    GSM1539614    GSM1539615    GSM1539616    GSM1539617 
##  Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA  
##  1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA  
##  Median : NA   Median : NA   Median : NA   Median : NA   Median : NA  
##  Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN  
##  3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA  
##  Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA  
##    GSM1539618    GSM1539619    GSM1539620    GSM1539621    GSM1539622 
##  Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA  
##  1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA  
##  Median : NA   Median : NA   Median : NA   Median : NA   Median : NA  
##  Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN  
##  3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA  
##  Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA  
##    GSM1539623    GSM1539624    GSM1539625    GSM1539626    GSM1539627 
##  Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA  
##  1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA  
##  Median : NA   Median : NA   Median : NA   Median : NA   Median : NA  
##  Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN  
##  3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA  
##  Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA  
##    GSM1539628    GSM1539629    GSM1539630    GSM1539631    GSM1539632 
##  Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA  
##  1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA  
##  Median : NA   Median : NA   Median : NA   Median : NA   Median : NA  
##  Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN  
##  3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA  
##  Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA  
##    GSM1539633    GSM1539634    GSM1539635    GSM1539636    GSM1539637 
##  Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA  
##  1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA  
##  Median : NA   Median : NA   Median : NA   Median : NA   Median : NA  
##  Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN  
##  3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA  
##  Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA  
##    GSM1539638    GSM1539639    GSM1539640    GSM1539641    GSM1539642 
##  Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA  
##  1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA  
##  Median : NA   Median : NA   Median : NA   Median : NA   Median : NA  
##  Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN  
##  3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA  
##  Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA  
##    GSM1539643    GSM1539644    GSM1539645    GSM1539646    GSM1539647 
##  Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA  
##  1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA  
##  Median : NA   Median : NA   Median : NA   Median : NA   Median : NA  
##  Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN  
##  3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA  
##  Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA  
##    GSM1539648    GSM1539649    GSM1539650    GSM1539651    GSM1539652 
##  Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA  
##  1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA  
##  Median : NA   Median : NA   Median : NA   Median : NA   Median : NA  
##  Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN  
##  3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA  
##  Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA  
##    GSM1539653    GSM1539654    GSM1539655    GSM1539656    GSM1539657 
##  Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA  
##  1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA  
##  Median : NA   Median : NA   Median : NA   Median : NA   Median : NA  
##  Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN  
##  3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA  
##  Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA  
##    GSM1539658    GSM1539659    GSM1539660    GSM1539661    GSM1539662 
##  Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA  
##  1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA  
##  Median : NA   Median : NA   Median : NA   Median : NA   Median : NA  
##  Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN  
##  3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA  
##  Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA  
##    GSM1539663    GSM1539664    GSM1539665    GSM1539666    GSM1539667 
##  Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA  
##  1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA  
##  Median : NA   Median : NA   Median : NA   Median : NA   Median : NA  
##  Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN  
##  3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA  
##  Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA  
##    GSM1539668    GSM1539669    GSM1539670    GSM1539671    GSM1539672 
##  Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA  
##  1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA  
##  Median : NA   Median : NA   Median : NA   Median : NA   Median : NA  
##  Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN  
##  3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA  
##  Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA  
##    GSM1539673    GSM1539674    GSM1539675    GSM1539676    GSM1539677 
##  Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA  
##  1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA  
##  Median : NA   Median : NA   Median : NA   Median : NA   Median : NA  
##  Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN  
##  3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA  
##  Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA  
##    GSM1539678    GSM1539679    GSM1539680    GSM1539681    GSM1539682 
##  Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA  
##  1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA  
##  Median : NA   Median : NA   Median : NA   Median : NA   Median : NA  
##  Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN  
##  3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA  
##  Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA  
##    GSM1539683    GSM1539684    GSM1539685    GSM1539686    GSM1539687 
##  Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA  
##  1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA  
##  Median : NA   Median : NA   Median : NA   Median : NA   Median : NA  
##  Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN  
##  3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA  
##  Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA  
##    GSM1539688    GSM1539689    GSM1539690    GSM1539691    GSM1539692 
##  Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA  
##  1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA  
##  Median : NA   Median : NA   Median : NA   Median : NA   Median : NA  
##  Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN  
##  3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA  
##  Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA  
##    GSM1539693    GSM1539694    GSM1539695    GSM1539696    GSM1539697 
##  Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA  
##  1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA  
##  Median : NA   Median : NA   Median : NA   Median : NA   Median : NA  
##  Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN  
##  3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA  
##  Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA  
##    GSM1539698    GSM1539699    GSM1539700    GSM1539701    GSM1539702 
##  Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA  
##  1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA  
##  Median : NA   Median : NA   Median : NA   Median : NA   Median : NA  
##  Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN  
##  3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA  
##  Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA  
##    GSM1539703    GSM1539704    GSM1539705    GSM1539706    GSM1539707 
##  Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA  
##  1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA  
##  Median : NA   Median : NA   Median : NA   Median : NA   Median : NA  
##  Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN  
##  3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA  
##  Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA  
##    GSM1539708    GSM1539709    GSM1539710    GSM1539711    GSM1539712 
##  Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA  
##  1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA  
##  Median : NA   Median : NA   Median : NA   Median : NA   Median : NA  
##  Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN  
##  3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA  
##  Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA  
##    GSM1539713    GSM1539714    GSM1539715    GSM1539716    GSM1539717 
##  Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA  
##  1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA  
##  Median : NA   Median : NA   Median : NA   Median : NA   Median : NA  
##  Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN  
##  3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA  
##  Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA  
##    GSM1539718    GSM1539719    GSM1539720    GSM1539721    GSM1539722 
##  Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA  
##  1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA  
##  Median : NA   Median : NA   Median : NA   Median : NA   Median : NA  
##  Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN  
##  3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA  
##  Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA  
##    GSM1539723    GSM1539724    GSM1539725    GSM1539726    GSM1539727 
##  Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA  
##  1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA  
##  Median : NA   Median : NA   Median : NA   Median : NA   Median : NA  
##  Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN  
##  3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA  
##  Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA  
##    GSM1539728    GSM1539729    GSM1539730    GSM1539731    GSM1539732 
##  Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA  
##  1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA  
##  Median : NA   Median : NA   Median : NA   Median : NA   Median : NA  
##  Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN  
##  3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA  
##  Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA  
##    GSM1539733    GSM1539734    GSM1539735    GSM1539736    GSM1539737 
##  Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA  
##  1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA  
##  Median : NA   Median : NA   Median : NA   Median : NA   Median : NA  
##  Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN  
##  3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA  
##  Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA  
##    GSM1539738    GSM1539739    GSM1539740    GSM1539741    GSM1539742 
##  Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA  
##  1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA  
##  Median : NA   Median : NA   Median : NA   Median : NA   Median : NA  
##  Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN  
##  3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA  
##  Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA  
##    GSM1539743    GSM1539744    GSM1539745    GSM1539746    GSM1539747 
##  Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA  
##  1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA  
##  Median : NA   Median : NA   Median : NA   Median : NA   Median : NA  
##  Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN  
##  3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA  
##  Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA  
##    GSM1539748    GSM1539749    GSM1539750    GSM1539751    GSM1539752 
##  Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA  
##  1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA  
##  Median : NA   Median : NA   Median : NA   Median : NA   Median : NA  
##  Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN  
##  3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA  
##  Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA  
##    GSM1539753    GSM1539754    GSM1539755    GSM1539756    GSM1539757 
##  Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA  
##  1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA  
##  Median : NA   Median : NA   Median : NA   Median : NA   Median : NA  
##  Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN  
##  3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA  
##  Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA  
##    GSM1539758    GSM1539759    GSM1539760    GSM1539761    GSM1539762 
##  Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA  
##  1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA  
##  Median : NA   Median : NA   Median : NA   Median : NA   Median : NA  
##  Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN  
##  3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA  
##  Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA  
##    GSM1539763    GSM1539764    GSM1539765    GSM1539766    GSM1539767 
##  Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA  
##  1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA  
##  Median : NA   Median : NA   Median : NA   Median : NA   Median : NA  
##  Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN  
##  3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA  
##  Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA  
##    GSM1539768    GSM1539769    GSM1539770    GSM1539771    GSM1539772 
##  Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA  
##  1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA  
##  Median : NA   Median : NA   Median : NA   Median : NA   Median : NA  
##  Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN  
##  3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA  
##  Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA  
##    GSM1539773    GSM1539774    GSM1539775    GSM1539776    GSM1539777 
##  Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA  
##  1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA  
##  Median : NA   Median : NA   Median : NA   Median : NA   Median : NA  
##  Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN  
##  3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA  
##  Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA  
##    GSM1539778    GSM1539779    GSM1539780    GSM1539781    GSM1539782 
##  Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA  
##  1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA  
##  Median : NA   Median : NA   Median : NA   Median : NA   Median : NA  
##  Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN  
##  3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA  
##  Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA  
##    GSM1539783    GSM1539784    GSM1539785    GSM1539786    GSM1539787 
##  Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA  
##  1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA  
##  Median : NA   Median : NA   Median : NA   Median : NA   Median : NA  
##  Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN  
##  3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA  
##  Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA  
##    GSM1539788    GSM1539789    GSM1539790    GSM1539791    GSM1539792 
##  Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA  
##  1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA  
##  Median : NA   Median : NA   Median : NA   Median : NA   Median : NA  
##  Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN  
##  3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA  
##  Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA  
##    GSM1539793    GSM1539794    GSM1539795    GSM1539796 
##  Min.   : NA   Min.   : NA   Min.   : NA   Min.   : NA  
##  1st Qu.: NA   1st Qu.: NA   1st Qu.: NA   1st Qu.: NA  
##  Median : NA   Median : NA   Median : NA   Median : NA  
##  Mean   :NaN   Mean   :NaN   Mean   :NaN   Mean   :NaN  
##  3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA   3rd Qu.: NA  
##  Max.   : NA   Max.   : NA   Max.   : NA   Max.   : NA
library(GEOquery)
## Loading required package: Biobase
## Warning: package 'Biobase' was built under R version 4.5.2
## Loading required package: BiocGenerics
## Warning: package 'BiocGenerics' was built under R version 4.5.2
## Loading required package: generics
## 
## Attaching package: 'generics'
## The following objects are masked from 'package:base':
## 
##     as.difftime, as.factor, as.ordered, intersect, is.element, setdiff,
##     setequal, union
## 
## Attaching package: 'BiocGenerics'
## The following objects are masked from 'package:stats':
## 
##     IQR, mad, sd, var, xtabs
## The following objects are masked from 'package:base':
## 
##     anyDuplicated, aperm, append, as.data.frame, basename, cbind,
##     colnames, dirname, do.call, duplicated, eval, evalq, Filter, Find,
##     get, grep, grepl, is.unsorted, lapply, Map, mapply, match, mget,
##     order, paste, pmax, pmax.int, pmin, pmin.int, Position, rank,
##     rbind, Reduce, rownames, sapply, saveRDS, table, tapply, unique,
##     unsplit, which.max, which.min
## Welcome to Bioconductor
## 
##     Vignettes contain introductory material; view with
##     'browseVignettes()'. To cite Bioconductor, see
##     'citation("Biobase")', and for packages 'citation("pkgname")'.
## Setting options('download.file.method.GEOquery'='auto')
## Setting options('GEOquery.inmemory.gpl'=FALSE)
library(pheatmap)
expr <- read.table("GSE63061_series_matrix.txt",
                   header = TRUE,
                   sep = "\t",
                   comment.char = "!",
                   check.names = FALSE,
                   stringsAsFactors = FALSE)

rownames(expr) <- expr[,1]
expr <- expr[,-1]

expr <- as.matrix(expr)
mode(expr) <- "numeric"
expr <- na.omit(expr)

dim(expr)
## [1] 32049   388
expr[1:5, 1:5]
##              GSM1539409 GSM1539410 GSM1539411 GSM1539412 GSM1539413
## ILMN_1343291  12.552807  12.711459  13.088393  12.643831  13.098389
## ILMN_1343295  10.101556   9.776015   9.594397  10.126782  10.223301
## ILMN_1651209   6.084671   6.255012   6.160485   6.109219   6.069960
## ILMN_1651210   6.068805   6.016468   6.024322   6.016118   6.056163
## ILMN_1651221   6.121060   6.173167   6.039552   6.111306   6.089542
gset <- getGEO("GSE63061", GSEMatrix = TRUE)
## Found 1 file(s)
## GSE63061_series_matrix.txt.gz
length(gset)
## [1] 1
gset <- gset[[1]]

pheno <- pData(gset)

dim(pheno)
## [1] 388  40
colnames(pheno)
##  [1] "title"                               "geo_accession"                      
##  [3] "status"                              "submission_date"                    
##  [5] "last_update_date"                    "type"                               
##  [7] "channel_count"                       "source_name_ch1"                    
##  [9] "organism_ch1"                        "characteristics_ch1"                
## [11] "characteristics_ch1.1"               "characteristics_ch1.2"              
## [13] "characteristics_ch1.3"               "characteristics_ch1.4"              
## [15] "characteristics_ch1.5"               "molecule_ch1"                       
## [17] "extract_protocol_ch1"                "label_ch1"                          
## [19] "label_protocol_ch1"                  "taxid_ch1"                          
## [21] "hyb_protocol"                        "scan_protocol"                      
## [23] "description"                         "data_processing"                    
## [25] "platform_id"                         "contact_name"                       
## [27] "contact_email"                       "contact_institute"                  
## [29] "contact_address"                     "contact_city"                       
## [31] "contact_zip/postal_code"             "contact_country"                    
## [33] "supplementary_file"                  "data_row_count"                     
## [35] "age:ch1"                             "ethnicity:ch1"                      
## [37] "gender:ch1"                          "included in case -control study:ch1"
## [39] "status:ch1"                          "tissue:ch1"
head(pheno[, 1:10])
##                   title geo_accession                status submission_date
## GSM1539409 7196843065_F    GSM1539409 Public on Aug 05 2015     Nov 06 2014
## GSM1539410 7196843076_G    GSM1539410 Public on Aug 05 2015     Nov 06 2014
## GSM1539411 7196843068_B    GSM1539411 Public on Aug 05 2015     Nov 06 2014
## GSM1539412 7196843063_B    GSM1539412 Public on Aug 05 2015     Nov 06 2014
## GSM1539413 7196843065_L    GSM1539413 Public on Aug 05 2015     Nov 06 2014
## GSM1539414 7196843066_H    GSM1539414 Public on Aug 05 2015     Nov 06 2014
##            last_update_date type channel_count source_name_ch1 organism_ch1
## GSM1539409      May 30 2024  RNA             1           Blood Homo sapiens
## GSM1539410      May 30 2024  RNA             1           Blood Homo sapiens
## GSM1539411      May 30 2024  RNA             1           Blood Homo sapiens
## GSM1539412      May 30 2024  RNA             1           Blood Homo sapiens
## GSM1539413      May 30 2024  RNA             1           Blood Homo sapiens
## GSM1539414      May 30 2024  RNA             1           Blood Homo sapiens
##            characteristics_ch1
## GSM1539409         status: MCI
## GSM1539410         status: MCI
## GSM1539411         status: MCI
## GSM1539412         status: MCI
## GSM1539413         status: MCI
## GSM1539414         status: MCI

Data Integration

Matched expression data with metadata using geo_accession Extracted disease status (group) from characteristics_ch1,Key finding: CTL (control),AD (Alzheimer’s Disease), MCI (mild cognitive impairment) and others, and I selcted the groups CTL: 134 AD: 139

grep("characteristics|group|diagnosis|disease|source|title", colnames(pheno), value = TRUE)
## [1] "title"                 "source_name_ch1"       "characteristics_ch1"  
## [4] "characteristics_ch1.1" "characteristics_ch1.2" "characteristics_ch1.3"
## [7] "characteristics_ch1.4" "characteristics_ch1.5"
candidate_cols <- grep("characteristics|group|diagnosis|disease|source|title",
                       colnames(pheno), value = TRUE)

for (cc in candidate_cols) {
  cat("\n====================\n")
  cat("Column:", cc, "\n")
  print(head(pheno[[cc]], 10))
}
## 
## ====================
## Column: title 
##  [1] "7196843065_F" "7196843076_G" "7196843068_B" "7196843063_B" "7196843065_L"
##  [6] "7196843066_H" "7943280031_C" "7943280031_J" "7196843035_B" "7196843053_L"
## 
## ====================
## Column: source_name_ch1 
##  [1] "Blood" "Blood" "Blood" "Blood" "Blood" "Blood" "Blood" "Blood" "Blood"
## [10] "Blood"
## 
## ====================
## Column: characteristics_ch1 
##  [1] "status: MCI" "status: MCI" "status: MCI" "status: MCI" "status: MCI"
##  [6] "status: MCI" "status: MCI" "status: MCI" "status: MCI" "status: MCI"
## 
## ====================
## Column: characteristics_ch1.1 
##  [1] "ethnicity: Western European"          
##  [2] "ethnicity: Western European"          
##  [3] "ethnicity: Western European"          
##  [4] "ethnicity: Western European"          
##  [5] "ethnicity: Other Caucasian"           
##  [6] "ethnicity: Other Caucasian"           
##  [7] "ethnicity: Western European"          
##  [8] "ethnicity: Any_Other_White_Background"
##  [9] "ethnicity: Western European"          
## [10] "ethnicity: Western European"          
## 
## ====================
## Column: characteristics_ch1.2 
##  [1] "age: 57" "age: 59" "age: 63" "age: 65" "age: 66" "age: 68" "age: 68"
##  [8] "age: 68" "age: 69" "age: 69"
## 
## ====================
## Column: characteristics_ch1.3 
##  [1] "gender: Female" "gender: Female" "gender: Female" "gender: Female"
##  [5] "gender: Female" "gender: Female" "gender: Female" "gender: Female"
##  [9] "gender: Female" "gender: Female"
## 
## ====================
## Column: characteristics_ch1.4 
##  [1] "included in case -control study: yes"
##  [2] "included in case -control study: yes"
##  [3] "included in case -control study: yes"
##  [4] "included in case -control study: yes"
##  [5] "included in case -control study: yes"
##  [6] "included in case -control study: yes"
##  [7] "included in case -control study: yes"
##  [8] "included in case -control study: yes"
##  [9] "included in case -control study: yes"
## [10] "included in case -control study: yes"
## 
## ====================
## Column: characteristics_ch1.5 
##  [1] "tissue: blood" "tissue: blood" "tissue: blood" "tissue: blood"
##  [5] "tissue: blood" "tissue: blood" "tissue: blood" "tissue: blood"
##  [9] "tissue: blood" "tissue: blood"
head(colnames(expr))
## [1] "GSM1539409" "GSM1539410" "GSM1539411" "GSM1539412" "GSM1539413"
## [6] "GSM1539414"
head(rownames(pheno))
## [1] "GSM1539409" "GSM1539410" "GSM1539411" "GSM1539412" "GSM1539413"
## [6] "GSM1539414"
head(pheno$geo_accession)
## [1] "GSM1539409" "GSM1539410" "GSM1539411" "GSM1539412" "GSM1539413"
## [6] "GSM1539414"
pheno2 <- pheno[match(colnames(expr), pheno$geo_accession), ]

all(pheno2$geo_accession == colnames(expr))
## [1] TRUE
char_cols <- grep("^characteristics_ch1", colnames(pheno2), value = TRUE)
char_cols
## [1] "characteristics_ch1"   "characteristics_ch1.1" "characteristics_ch1.2"
## [4] "characteristics_ch1.3" "characteristics_ch1.4" "characteristics_ch1.5"
for (cc in char_cols) {
  cat("\n====================\n")
  cat("Column:", cc, "\n")
  print(unique(pheno2[[cc]])[1:20])
}
## 
## ====================
## Column: characteristics_ch1 
##  [1] "status: MCI"            "status: CTL"            "status: AD"            
##  [4] "status: borderline MCI" "status: OTHER"          "status: CTL to AD"     
##  [7] "status: MCI to CTL"     NA                       NA                      
## [10] NA                       NA                       NA                      
## [13] NA                       NA                       NA                      
## [16] NA                       NA                       NA                      
## [19] NA                       NA                      
## 
## ====================
## Column: characteristics_ch1.1 
##  [1] "ethnicity: Western European"                                                            
##  [2] "ethnicity: Other Caucasian"                                                             
##  [3] "ethnicity: Any_Other_White_Background"                                                  
##  [4] "ethnicity: Caribbean"                                                                   
##  [5] "ethnicity: Irish"                                                                       
##  [6] "ethnicity: British"                                                                     
##  [7] "ethnicity: Indian"                                                                      
##  [8] "ethnicity: British_English"                                                             
##  [9] "ethnicity: British English"                                                             
## [10] "ethnicity: British_Welsh"                                                               
## [11] "ethnicity: Any_Other_Asian_Background"                                                  
## [12] "ethnicity: White_And_Asian"                                                             
## [13] "ethnicity: British_Scottish"                                                            
## [14] "ethnicity: British_Other_Background"                                                    
## [15] "ethnicity: Any_Other_Ethnic_Background"                                                 
## [16] "ethnicity: Asian"                                                                       
## [17] "ethnicity: Any_Other_Black_Background"                                                  
## [18] "ethnicity: unkown but she's white and speaks english with a slight south african accent"
## [19] NA                                                                                       
## [20] NA                                                                                       
## 
## ====================
## Column: characteristics_ch1.2 
##  [1] "age: 57" "age: 59" "age: 63" "age: 65" "age: 66" "age: 68" "age: 69"
##  [8] "age: 70" "age: 71" "age: 73" "age: 74" "age: 75" "age: 64" "age: 67"
## [15] "age: 72" "age: 60" "age: 61" "age: 62" "age: 85" "age: 81"
## 
## ====================
## Column: characteristics_ch1.3 
##  [1] "gender: Female" "gender: Male"   NA               NA              
##  [5] NA               NA               NA               NA              
##  [9] NA               NA               NA               NA              
## [13] NA               NA               NA               NA              
## [17] NA               NA               NA               NA              
## 
## ====================
## Column: characteristics_ch1.4 
##  [1] "included in case -control study: yes"
##  [2] "included in case -control study: no" 
##  [3] NA                                    
##  [4] NA                                    
##  [5] NA                                    
##  [6] NA                                    
##  [7] NA                                    
##  [8] NA                                    
##  [9] NA                                    
## [10] NA                                    
## [11] NA                                    
## [12] NA                                    
## [13] NA                                    
## [14] NA                                    
## [15] NA                                    
## [16] NA                                    
## [17] NA                                    
## [18] NA                                    
## [19] NA                                    
## [20] NA                                    
## 
## ====================
## Column: characteristics_ch1.5 
##  [1] "tissue: blood" NA              NA              NA             
##  [5] NA              NA              NA              NA             
##  [9] NA              NA              NA              NA             
## [13] NA              NA              NA              NA             
## [17] NA              NA              NA              NA
group_raw <- pheno2$characteristics_ch1
table(group_raw, useNA = "ifany")
## group_raw
##             status: AD status: borderline MCI            status: CTL 
##                    139                      3                    134 
##      status: CTL to AD            status: MCI     status: MCI to CTL 
##                      1                    109                      1 
##          status: OTHER 
##                      1
group <- sub("status: ", "", group_raw)
group <- trimws(group)

table(group, useNA = "ifany")
## group
##             AD borderline MCI            CTL      CTL to AD            MCI 
##            139              3            134              1            109 
##     MCI to CTL          OTHER 
##              1              1
keep <- group %in% c("AD", "CTL")

expr_sub <- expr[, keep]
group_sub <- group[keep]
pheno_sub <- pheno2[keep, ]

table(group_sub)
## group_sub
##  AD CTL 
## 139 134
dim(expr_sub)
## [1] 32049   273
group_sub <- factor(group_sub, levels = c("CTL", "AD"))
table(group_sub)
## group_sub
## CTL  AD 
## 134 139

Boxplot — Expression Distribution

Data is well normalized, with no major batch effects or systematic bias.CTL and AD samples have very similar distributions

cols <- c("steelblue", "tomato")[group_sub]

boxplot(expr_sub,
        outline = FALSE,
        las = 2,
        col = cols,
        main = "Expression Distribution: CTL vs AD")
legend("topright",
       legend = levels(group_sub),
       fill = c("steelblue", "tomato"))

PCA — Sample Structure

Differential Expression Analysis (limma)

A large number of genes are significantly differentially expressed between AD and CTL samples, despite the weak global separation observed in PCA.

library(limma)
## Warning: package 'limma' was built under R version 4.5.2
## 
## Attaching package: 'limma'
## The following object is masked from 'package:BiocGenerics':
## 
##     plotMA
design <- model.matrix(~ group_sub)
colnames(design) <- c("Intercept", "AD_vs_CTL")
design
##     Intercept AD_vs_CTL
## 1           1         0
## 2           1         0
## 3           1         0
## 4           1         0
## 5           1         0
## 6           1         0
## 7           1         0
## 8           1         0
## 9           1         0
## 10          1         0
## 11          1         0
## 12          1         0
## 13          1         0
## 14          1         0
## 15          1         0
## 16          1         0
## 17          1         0
## 18          1         0
## 19          1         0
## 20          1         0
## 21          1         0
## 22          1         0
## 23          1         0
## 24          1         0
## 25          1         0
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## 30          1         0
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## 40          1         0
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## 42          1         0
## 43          1         0
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## 45          1         0
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## 48          1         0
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## 50          1         0
## 51          1         0
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## 72          1         0
## 73          1         1
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## 80          1         1
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## 86          1         1
## 87          1         1
## 88          1         1
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## 90          1         1
## 91          1         1
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## 154         1         1
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## attr(,"assign")
## [1] 0 1
## attr(,"contrasts")
## attr(,"contrasts")$group_sub
## [1] "contr.treatment"
fit <- lmFit(expr_sub, design)
fit <- eBayes(fit)

deg <- topTable(fit,
                coef = "AD_vs_CTL",
                number = Inf,
                adjust.method = "BH")

head(deg)
##                   logFC   AveExpr         t      P.Value    adj.P.Val        B
## ILMN_2189936 -0.4466342 10.408005 -9.435752 1.795640e-18 5.754846e-14 31.18884
## ILMN_2189933 -0.4533286  9.692502 -8.645821 4.653621e-16 5.267952e-12 25.71159
## ILMN_1792528 -0.4550236 12.015340 -8.637390 4.931154e-16 5.267952e-12 25.65455
## ILMN_1784286 -0.4976969  8.390367 -8.457838 1.680800e-15 1.346699e-11 24.44740
## ILMN_1746516 -0.4569375 11.722748 -8.358204 3.298724e-15 2.114416e-11 23.78391
## ILMN_1776104 -0.4219056  7.686509 -8.107747 1.760727e-14 9.404925e-11 22.13674

Volcano Plot

Most differentially expressed genes show modest fold changes but high statistical significance, indicating subtle but consistent transcriptional differences between AD and CTL.

plot(deg$logFC, -log10(deg$P.Value),
     pch = 20,
     main = "Volcano Plot: AD vs CTL",
     xlab = "logFC",
     ylab = "-log10(P.Value)")

sig <- deg$adj.P.Val < 0.05 & abs(deg$logFC) > 1
points(deg$logFC[sig], -log10(deg$P.Value[sig]), pch = 20, col = "red")
abline(v = c(-1, 1), col = "blue", lty = 2)
abline(h = -log10(0.05), col = "blue", lty = 2)

The exploratory data analysis indicates that the dataset is well normalized and suitable for downstream analysis. Although AD and control samples do not show strong global separation in PCA, we observe significant gene-level differences through differential expression analysis.Importantly, we do not observe a small number of highly dominant genes. Instead, many genes exhibit modest but statistically significant changes. This suggests that Alzheimer’s disease is driven by coordinated, system-level transcriptional changes rather than a single key biomarker. Therefore, this dataset is particularly suitable for identifying potential biomarkers and, more importantly, for pathway-level analysis to better understand disease mechanisms.