MTHFR and colorectal carcinoma: For SNPs PTGS1 c.639C>A (p.Gly213Gly), IL8 c.-352T>A, and MTHFR c.1286A>C (p.Ala429Glu), minor alleles appeared associated with an increase in CRC, whereas for SNPs PLA2G2A c.435+230C>T, PPARG c.1431C>T (p.His477His), they were associated with a decrease in CRC risk.