POLA2 and colorectal cancer: The representative pathways and genes for these 5 clusters were “Sphingolipid metabolism” (with 3 genes involved: CERS2, GBA, GLB1), “Transcriptional regulation of white adipocyte differentiation” (with 4 genes involved: CDK8, MED1, MED28, MED31), “G1 to S cell cycle control” (with 3 genes involved: CDC25A, POLA2, PRIM1), “Ethanol effects on histone modifications” (with 4 genes involved: ACSS2, ATF2, MED1, HDAC7) and “Chromosomal and microsatellite instability in colorectal cancer” (with 6 genes involved: RHOA, SMAD3, TCF7L2, CDK8, ATF2, PLEC).