CDKN2A and colorectal carcinoma: Evidence shows that this abnormal methylation has been found in the promoter regions of some vital tumor suppressor genes in CRC, including O6-methylguanine-DNA methyltransferase (MGMT), thrombospondin 1 (THBS1), tissue inhibitor of metalloproteinases 3 (TIMP3), p14ARF, p15INK4B (cyclin dependent kinase inhibitor 2B), p16INK4a, adenomatous polyposis coli (APC), deleted in colorectal carcinoma (DCC), MutL homolog 1 (MLH1), insulin-like growth factor 2 (IGF2), suppressor of cytokine signaling 1 (SOCS-1) and Runt-related transcription factor 3 (RUNX3) genes.