ABL1 and chronic myelogenous leukemia, BCR-ABL1 positive: Bosutinib (BOS; Figure 1) is a second-generation dual Abl/Src inhibitor that shows potent inhibition of the growth of CML cells in vitro, is also active against multiple imatinib-resistant BCR-Abl mutations, and has proven efficacy in current clinical trials for imatinib-resistant CML [10,11,12].