SMAD4 and Peutz-Jeghers syndrome: Previous research has identified correlations between P germline mutations and hereditary CRC, including MLH1/MSH2/MSH6/PMS2 mutations with Lynch syndrome (also known as hereditary non-polyposis CRC), APC mutations with FAP, MUTYH mutations with MUTYH-associated polyposis, STK11 mutations with Peutz-Jeghers syndrome, SMAD4/BMPR1A mutations with juvenile polyposis syndrome, PTEN mutations with PTEN hamartoma tumor syndrome, and RNF43 mutations with serrated polyposis syndrome4–7.