ABL1 and chronic myelogenous leukemia, BCR-ABL1 positive: Chronic myeloid leukemia (CML) is a clonal myeloproliferative neoplasm characterized by the unregulated proliferation of myeloid cells in the bone marrow with the presence of a reciprocal translocation between chromosomes 9 and 22, or the Philadelphia chromosome (Ph), causing the formation of the BCR-ABL fusion gene, encoding the oncogenic tyrosine kinase BCR-ABL [1].