This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Thyroid Tumor, Subject name: Pathology
RET proto-oncogene is associated with:- 
Select and explain. 
A. Medullary thyroid cancer, B. Paraganglioma, C. Papillary thyroid cancer, D. CNS tumors
A: Medullary thyroid cancer
Answer: A: Medullary thyroid cancer 
Explanation: RET proto-oncogene: Associated with development of MEN II syndrome (affects thyroid & adrenal medulla) Therefore, patients have risk of developing medullary thyroid cancer & pheochromocytoma. Thyroid tumors & associated mutations: - Papillary thyroid cancer: RET-PTC gene - Follicular thyroid cancer: RAS gene - Anaplastic thyroid cancer: p53 gene