Newer BCR–ABL inhibitors (dasatinib, nilotinib, bosutinib, and ponatinib) were developed to overcome imatinib resistance/intolerance, and most are approved for the second-line treatment for chronic phase (CP), accelerated phase (AP), or blast phase (BP) CML or Ph+ acute lymphoblastic leukemia (ALL; dasatinib and ponatinib only) resistant or intolerant to prior imatinib treatment (nilotinib is not approved for CML-BP). This evidence concerns the gene ABL1 and acute lymphoblastic leukemia.