RAD51 and colorectal cancer: Our results confirmed that RAD51 (rs1801320) and XRCC2 (rs3218536) genes have increased probability of colorectal cancer and both genes are significantly associated with colorectal cancer occurrence and further elucidate the relationship of multiple genotypes at the RAD51(rs1801320) and XRCC2 (rs3218536) locus with colorectal cancer occurrence.