This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Urology, Subject name: Surgery
Imatinib mesylate used in the treatment of GIST is a inhibitor of 
Select and explain. 
A. IL-12, B. TNF-x, C. Tyrosine kinase, D. VEGE
C: Tyrosine kinase
Answer: C: Tyrosine kinase 
Explanation: Imatinib mesylate used in the treatment of GIST ( GastroIntestinal Stromal Tumours) is a c-kit(transmembrane receptor tyrosine kinase) tyrosine kinase inhibitor. GIST is rare but most common nonepithelial small bowel tumours. More than 95% show c-kit mutation. Reference : page 877 SRB's manual of surgery 5th edition