Mutations in MMR genes including MSH2 (MutS Homolog 2), MLH1 (MutL homolog 1), PMS1 (PMS1 homolog 1), PMS2 (PMS homolog 2) or MSH6 (MutS Homolog 6) subsequently give rise to a highly penetrant autosomal dominant predisposition cancer known as Lynch syndrome that increase risk for colon, endometrial, prostate, and other cancers. Here, MLH1 is linked to Lynch syndrome.