ABL1 and chronic myelogenous leukemia, BCR-ABL1 positive: Chronic myeloid leukemia (CML) is a rare hematopoietic neoplasm predominantly caused by reciprocal translocation t (9; 22) (q34; q11), resulting in the formation of the BCR::ABL1 fusion gene, which is considered as the hallmark of the disease (Nowell and Hungerford, 1960; Rowley, 1973).