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