BCR and chronic myelogenous leukemia, BCR-ABL1 positive: Chronic Myeloid Leukaemia (CML) is a clonal haematopoietic stem cell disorder characterised by the pathognomonic reciprocal translocation t(9;22)q34 encoding the BCR::ABL1 fusion oncoprotein, which can be targeted therapeutically using tyrosine kinase inhibitors (TKI).