CACNA2D1 and colorectal carcinoma: Eighteen hub genes in the brown gene module were identified negatively correlated with CRC, including HAND2-AS1, LMO3, AGTR1, PDZRN4, RBPMS2, LMOD1, GPM6A, CASQ2, CACNA2D1, RNF150, ANGPTL1, HSPB8, SCN7A, CSPG4, DDR2, BNC2, TSPYL5 and PEG3.