atypical chronic myeloid leukemia, BCR-ABL1 negative (MONDO_0004653, a Monarch Disease Ontology id) is a myelodysplastic/myeloproliferative neoplasm characterized by the principal involvement of the neutrophil series with leukocytosis and multilineage dysplasia. The neoplastic cells do not have a Philadelphia chromosome or the BCR/ABL fusion gene. (WHO, 2001). Also known as: aCML, atypical CML, atypical chronic myeloid leukaemia, atypical chronic myeloid leukaemia BCR-ABL1 negative, atypical chronic myeloid leukemia, atypical chronic myeloid leukemia BCR-ABL1 negative, atypical chronic myeloid leukemia, BCR-ABL1 Negative, subacute granulocytic leukaemia.