Germline mutations in the MMR genes MSH2, MLH1, PMS2, and MSH6 are causal for Lynch syndrome, an inherited condition in which patients may develop colorectal cancer (CRC) (constituting ∼3% of all CRCs) and cancers of the rest of the gastrointestinal tract, female reproductive and urinary tracts, and specific skin and CNS tumors (4). This evidence concerns the gene MLH1 and colorectal carcinoma.