Gastrointestinal stromal tumors (GIST) are defined by mutated and over-expressed oncogenic receptor tyrosine kinases (RTKs) c-Kit or α-PDGFR that are also effective therapeutic targets for which imatinib mesylate [IM (gleevec), Novartis Pharmaceuticals] an ATP-site small molecule tyrosine kinase inhibitor (TKI) is approved as frontline therapy in the advanced [1-4] and adjuvant [5] settings. This evidence concerns the gene KIT and gastrointestinal stromal tumor.