<prompt> The gene involved in GIST -C-KITBRAC-1p53BRAC-2  <response>: Ans. is a i.e., C-KIT Pathogenesis of GISTs o Approximately 75 to 80 of all GISTs have oncogenic, gain-of-function mutations of gene encoding the tyrosine kinase c-KIT o Approximately 8 of GISTs have mutations that activate a related tyrosine kinase, platelet derived growth factor receptor a PDGFRA. o Consitutively active c-KIT or PDGFRA receptor tyrosine kinases activate RAS and P13KAKT pathways and thereby promote tumor cell proliferation. 