BCR and chronic myelogenous leukemia, BCR-ABL1 positive: Chronic Myeloid Leukaemia (CML) is a model for modern precision medicine, where treatment is tailored to a patient's genetic profile.All CML patients exhibit the t (9:22) chromosomal translocation, resulting in the fusion of the BCR gene from chromosome 22 and the ABLkinase domain from chromosome 9.