BCR and chronic myelogenous leukemia, BCR-ABL1 positive: Chronic myelogeneous leukemia (CML) is a clonal disease that originates from a single transformed hematopoietic stem cell (HSC) or multipotent progenitor cell harboring a chromosomal translocation between chromosome 9 and 22 [t(9;22)(q34;q11)], resulting in the formation of Philadelphia(Ph) chromosome and at the molecular level, a chimeric gene known as BCR-ABL responsible for CML initiation.