ABL1 and chronic myelogenous leukemia, BCR-ABL1 positive: Whereas patients with CML were historically faced with a dismal prognosis, the BCR-ABL tyrosine kinase inhibitor (TKI) era, heralded by imatinib, has vastly decreased the numbers of patients progressing from chronic (CP) to accelerated phase (AP) or blast phase (BP) CML and has improved patient survival (Agrawal, Garg, Cortes, & Quintás-Cardama, 2010).