Therefore, we carried out this case-control study in a Chinese Han population to determine whether MTHFR tagging SNPs (rs3753584 T>C, rs9651118 T>C, rs1801133 G>A, rs4846048 A>G and rs4845882 G>A) were associated with the risk of CRC. Here, MTHFR is linked to colorectal carcinoma.