BCR and chronic myelogenous leukemia, BCR-ABL1 positive: Chronic myeloid leukemia (CML) is a malignant hemopathy resulting from reciprocal translocation of ABL1 from chromosome 9 and BCR from chromosome 22 leading to the formation of a hybrid BCR::ABL gene from which a new BCR::ABL protein is derived, that plays a central role in the development of chronic myeloid leukemia [1].