Table 1. Characteristics of datasets in this study.

Dataset	Platform	Number of samples (tumor/control)	Tumor type
GSE15471	GPL570[(HG-U133_Plus_2) Affymetrix Human Genome U133 Plus 2.0 Array]	78 (39/39)	Pancreatic cancer
GSE28735	GPL6244[(HuGene-1_0-st) Affymetrix Human Gene 1.0 ST Array]	90 (45/45)	Pancreatic cancer
GSE32676	GPL570[(HG-U133_Plus_2) Affymetrix Human Genome U133 Plus 2.0 Array]	32 (25/7)	Pancreatic cancer
GSE39751	GPL5936 (HEEBO Human oligo array)	24 (12/12)	Pancreatic cancer
GSE43795	GPL10558(Illumina HumanHT-12 V4.0 expression beadchip)	31 (26/5)	Pancreatic cancer
GSE55643	GPL6480 (Agilent-01485 0 Whole Human Genome Microarray 4x44K G4112F)	53 (45/8)	Pancreatic cancer
GSE62165	GPL13667[(HG-U219) Affymetrix Human Genome U219 Array]	131 (118/13)	Pancreatic cancer
GSE62452	GPL6244[(HuGene-1_0-st) Affymetrix Human Gene 1.0 ST Array]	130 (61/69)	Pancreatic cancer
TCGA	Illumina HiSeq	182 (178/4)	Pancreatic cancer