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
BRAF gene mutation is seen in 
Select and explain. 
A. Breast carcinoma, B. Melanoma, C. Osteosarcoma, D. Prostate carcinoma
B: Melanoma
Answer: B: Melanoma 
Explanation: Somatic activating mutations in the proto-oncogenes BRAF or NRAS are observed in a high propoion of melanomas. These mutations, which promote cellular proliferation and survival by activating the extracellular signal-regulated protein kinase (ERK) pathway, generally are mutually exclusive, since BRAF functions downstream of RAS. (Robbins Basic Pathology, 9 th edition. page : 867)