This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pathology
[{'content': 'Mutation in which of the following tumour suppressor gene causes carcinoma? \nSelect and explain. \nA. p53, B. p51, C. Ro, D. All of the above', 'role': 'user'}, {'content': "Answer: A \nExplanation: If the p53 gene is mutated, the protection offered by the p53 tumor suppressor protein against DNA damage (for example, ras oncogene mutation) is lost. If a cell becomes homozygous for the mutant allele, that is ‘loses heterozygosity’, cancer may develop.\nRef: Shafer's textbook of oral pathology 7th edition page 108", 'role': 'assistant'}]