ABL1 and chronic myelogenous leukemia, BCR-ABL1 positive: CML (chronic myeloid leukemia) or chronic granulocytic leukaemia is one of the myeloproliferative neoplasms (MPN) characterized by proliferation of a pluripotential stem cell that can differentiate along the granulocytic lineage and is consistently associated with the BCR-ABL1 fusion gene (1).