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 "Governor of proliferation" \nSelect and explain. \nA. RB, B. TP53, C. APC, D. Patched', 'role': 'user'}, {'content': 'Answer: A \nExplanation: The retinoblastoma (Rb) gene First discovered TSG On chr locus 13q14 Gene product: RB protein Inactivation - first discovered in Retinoblastoma Familial/Hereditary (40%) Sporadic Key negative regulator of G1/S transition "Governor of proliferation"', 'role': 'assistant'}]