This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Tumors, Subject name: Pathology
[{'content': 'Which of the following mutation is seen in Cowden syndrome? \nSelect and explain. \nA. STK 11 mutation, B. SMAD 4 mutation, C. PTEN mutation, D. PTCH mutation', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Mutation in PTEN gene: Breast tumors Endometrial tumors Skin appendage tumors Thyroid tumors Cowden syndrome: Dysplastic gangliogliocytoma of the cerebellum (Lhermitte Duclos disease), caused by mutations in PTEN resulting in PI3K/AKT signaling pathway PTEN', 'role': 'assistant'}]