MLH1 and Lynch syndrome: The specific Mendelian CRC syndromes (and their mutant genes) are familial adenomatous polyposis (APC), Lynch syndrome/HNPCC (mismatch repair genes MSH2, MLH1, MSH6, PMS2), Peutz–Jeghers syndrome (LKB1/STK11), juvenile polyposis (SMAD4, BMPR1A), MUTYH-associated polyposis (the base excision repair gene MUTYH), and hereditary mixed polyposis (GREM1).