BCR and chronic myelogenous leukemia, BCR-ABL1 positive: Chronic myeloid leukemia (CML) has been identified as a hematologic disorder, which features the reciprocal translocation between the Abelson leukemia virus oncogene (ABL) localized in chromosome 9 (also named the Philadelphia (Ph) chromosome) and the break-point cluster (BCR) gene localized in chromosome 22.