BCR and chronic myelogenous leukemia, BCR-ABL1 positive: Chronic myelogenous leukemia (CML) is a hematopoietic stem cell malignancy characterized by the t(9;22)(q34;q11) balanced reciprocal translocation of the Philadelphia (Ph) chromosome, which leads to the generation of BCR-ABL oncogenic fusion gene that encodes the chimeric BCR-ABL protein with constitutive kinase activity1,2.