BCR and chronic myelogenous leukemia, BCR-ABL1 positive: Due to the success of tyrosine kinase inhibitor (TKI) therapy, chronic myeloid leukaemia (CML), a rare myeloproliferative disease arising through the acquisition of BCR::ABL1 in a haematopoietic stem cell (HSC)1, is predicted to become the most prevalent form of leukaemia within 30 years2.