According to the international scale (BCR-ABLIS), BCR-ABL transcript levels > 10% at 3 months are associated with reduced rates of event-free survival (EFS), progression-free survival (PFS), and overall survival (OS).16–18 Furthermore, Branford et al demonstrated that the BCR-ABLIS at 3 months independently predicted stable and undetectable BCR-ABL.19 At present, the failure to generate an early molecular response (EMR) to imatinib is a widely used criterion for switching to a second-generation TKI in chronic-phase CML (CML-CP).2,20. This evidence concerns the gene ABL1 and chronic myelogenous leukemia, BCR-ABL1 positive.