ABL1 and chronic myelogenous leukemia, BCR-ABL1 positive: Chronic myeloid leukemia (CML) is a myeloproliferative disorder, characterized by balanced reciprocal translocation between chromosomes 9 and 22, with the subsequent generation of the BCR–ABL1 oncogenic fusion gene that encodes the chimeric BCR–ABL1 protein with enhanced tyrosine kinase activity [1,2].