BCR and chronic myelogenous leukemia, BCR-ABL1 positive: Tyrosine kinase inhibitors (TKIs) represent the frontline treatment against chronic myeloid leukemia (CML), characterized by the t(9:22) chromosomal translocation, resulting in the breakpoint cluster region-Abelson (BCR-ABL)1 fusion oncogene with constitutively activated Abl tyrosine kinase activity.