 Chronic myeloid leukemia (CML) is a myeloproliferative disorder characterized by a triphasic clinical course, the morphologic expansion of a terminally differentiated myeloid cell and the presence of the BCR-ABL1 fusion gene, the hallmark of CML.     ///    "Conventional cytogenetic, fluorescence in situ hybridization, and molecular testing for the BCR-ABL1 fusion gene are key investigations for the diagnosis and monitoring of CML. "    ///    "The fusion gene is usually, but not always, associated with a Philadelphia chromosome, the result of a reciprocal exchange of genetic material between chromosome 22 and chromosome 9, which leads to the production of the activated BCR-ABL1 gene and oncoprotein. "    ///    Technical aspects and clinical applications of measuring BCR-ABL1 transcripts number in chronic myeloid leukemia.. 