This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Large intestine, Subject name: Surgery
[{'content': 'Genetic abnormality in case of late adenoma to carcinoma in Ca colon: \nSelect and explain. \nA. APC, B. K-ras, C. DCC, D. p53', 'role': 'user'}, {'content': 'Answer: D \nExplanation: The most frequently mutated tumor suppressor gene in human neoplasia is p53 (TP53), located on chromosomes 17p. Mutations in p53 are present in 75% of colorectal cancers and occurs, rather late in the adenoma-carcinoma sequence. FEARON - VOGELSTEIN ADENOMA CARCINOMA MULTISTEP MODEL', 'role': 'assistant'}]