ABL1 and chronic myelogenous leukemia, BCR-ABL1 positive: Despite the success of TKIs, there is still a possibility that some CML patients become resistant to front-line treatment with imatinib, and to second generation TKIs (e.g. nilotinib, dasatinib) through the BCR-ABL T315I mutation wherein only third generation TKIs (e.g. ponatinib) are efficacious.