ABL1 and chronic myelogenous leukemia, BCR-ABL1 positive: The mechanisms underlying imatinib resistance are BCR‐ABL kinase-dependent (e.g., point mutations in the BCR-ABL tyrosine kinase domain (TKD) or augmented expression of the BCR-ABL) 8; and BCR-ABL independent (e.g., persistence of quiescent CML stem cell or alterations of efflux influx pumps 9.