KIT and chronic myelogenous leukemia, BCR-ABL1 positive: Imatinibwas the first drug developed to inhibit the BCR-ABL tyrosine kinases in Philadelphia-chromosome-positive chronic myelogenous leukemia, c-kit in rare gastrointestinal stromal tumors (that present KIT mutations) and several platelet-derived growth factor receptors (PDGFRs) in other forms of cancer [41].