Germline mutations in MMR genes, most commonly MLH1, MSH2, MSH6 and PMS2, are causative for Lynch syndrome, a cancer predisposition condition associated with increased lifetime risk to develop colorectal cancer (CRC) or other tumor types including endometrial and gastric carcinoma (Hampel et al., 2005; Lynch and Krush, 1971; Lynch et al., 2015). This evidence concerns the gene MLH1 and colorectal carcinoma.