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': 'The gene involved in GIST \nSelect and explain. \nA. C-KIT, B. BRAC-1, C. p53, D. BRAC-2', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Pathogenesis of GISTs\n\nApproximately 75% to 80% of all GISTs have oncogenic, gain-of-function mutations of the gene encoding the\xa0tyrosine kinase c-KIT.\nApproximately 8% of GISTs have mutations that activate a related tyrosine kinase,\xa0platelet-derived growth factor receptor\xa0a\xa0(PDGFRA).\nConstitutively active c-KIT or PDGFRA receptor tyrosine kinases activate\xa0RAS and P13K/AKT pathways\xa0and thereby promote tumor cell proliferation.', 'role': 'assistant'}]