CDK4 and chronic myelogenous leukemia, BCR-ABL1 positive: The first type of this drug was imatinib mesylate (Gleevec, also known as STI–571) for chronic myelogenous leukemia (CML)3,4, which was followed by various drugs including tyrosine kinase inhibitors, Raf inhibitors, MEK inhibitors, CDK4/6 inhibitors, and monoclonal antibodies specifically recognizing receptors on the cancer cell surface.