This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General pathology, Subject name: Pathology
[{'content': 'Following is called "gatekeeper of colonic neoplasia" \nSelect and explain. \nA. APC, B. SMAD2, C. PTEN, D. STK11', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Adenomatous polyposis coli (APC) gene Chr 5q21 Gate-keeper of colonic neoplasia Component of WNT signalling pathway Controls cell fate, polarity and adhesion during embryonic devt Controls oncogenic effect of b catenin Germline LOF mutation - Familial Adenomatous Polyposis Colon Cancer (AD) Other tumours - hepatoblastoma, HCC', 'role': 'assistant'}]