This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: G.I.T, Subject name: Pathology
Specific for GIST tumor is - 
Select and explain. 
A. CD117, B. CD29, C. CD34, D. CD23
A: CD117
Answer: A: CD117 
Explanation: About 80% of all GISTs have oncogenic,gain of function mutations of the gene coding the tyrosine kinase c-KIT or CD117 GENERAL AND SYSTEMIC PATHOLOGY RAMDAS NAYAK PAGE NO:390