Commonest mutations that are associated with GIST are in

Approximately 75% to 80% of all GISTs have oncogenic, gain-of-function mutations in the receptor tyrosine kinase KIT. (C-KIT or CD 117)Approximately 8% of GISTs have mutations that activate a closely related receptor tyrosine kinase, platelet-derived growth factor receptor a (PDGFRA).Some GISTs without mutated KIT or PDGFRA have mutations in other genes that function in these pathways (NF1, BRAF, HRAS, or NRAS).Ref: Robbins Pathology; 9th edition; Page no: 775