For example, imatinib mesylate (IM, Gleevec; Novartis), an inhibitor of Bcr-Abl, c-Kit and platelet-derived growth factor receptor (PDGFR), has been successfully used in the treatments of chronic myeloid leukemia (CML) and gastrointestinal stromal tumors (GISTs) [12]. This evidence concerns the gene PDGFRB and gastrointestinal stromal tumor.