<prompt> Which of the following mutation seen in Cowden syndrome?PTCH mutationPTEN mutationSTK11 mutationSMAD4 mutation  <response>: Ans. b. PTEN mutationRef: Robbins and Cotran Pathologic Basis of Disease 9th Ed; Page No-291Tumor suppressor genes and associated with syndromesGeneProteinFunctionFamilial syndromesPTCHPatchedInhibitor of Hedgehog signalingGorlin syndrome basal cell carcinoma, medulloblastoma, several benign tumorsPTENPhosphatase and tensin homologueInhibitor of PI3KAKT signalingCowden syndrome variety of benign skin, Gl, and CNS growths; breast, endometrial, and thyroid carcinomaSTK11Liver kinase B1 LKB1 or STK11Activator of AMPK family of kinases; suppresses cell growth when cell nutrient and energy levels are lowPeutz-Jeghers syndrome Gl polyps, Gl cancers, pancreatic carcinoma and other carcinomasSMAD4SMAD4Component of the TGFP signaling pathway, repressors of MYC and CDK4 expression, inducers of CDK inhibitor expressionJuvenile polyposis, pancreatic carcinoma 