head(ctrl.data)[1:6,1:6]

 head(ctrl.data)[1:6,1:6]
     id         PT089_P1_A01 PT089_P1_A02 PT089_P1_A03 PT089_P1_A04 PT089_P1_A05
[1,] "A1BG"     "    0.00"   "    0.00"   "    0.00"   "    0.00"   "    0.00"  
[2,] "A1BG-AS1" "    0.00"   "    0.00"   "    0.00"   "    0.00"   "    0.00"  
[3,] "A1CF"     "    0.00"   "    0.00"   "    0.00"   "    1.00"   "    0.00"  
[4,] "A2M"      "    0.00"   "    0.00"   "    0.00"   "  339.00"   "    0.00"  
[5,] "A2M-AS1"  "    0.00"   "    0.00"   "    0.00"   "    0.00"   "    0.00"  
[6,] "A2ML1"    "    1.08"   "    0.00"   "    0.00"   "    0.00"   "    0.00"  
>