KIT and chronic myelogenous leukemia, BCR-ABL1 positive: Imatinib (Glivec ®) is a highly selective inhibitor of the RTK family comprising Abl, the Bcr-Abl fusion protein found in most cases of chronic myeloid leukemia (CML), PDGFR- α and -β, and the product of the c-kit proto-oncogene (KIT).