ABL1 and chronic myelogenous leukemia, BCR-ABL1 positive: These chimeric genes encode BCR-ABL oncoproteins which contains the activated tyrosine kinase region of ABL, causing aberrant tyrosine kinase activity and hence promotes the proliferation of CML cells (National Comprehensive Cancer Network Clinical Practice Guidelines in Oncology, Chronic Myelogenous Leukemia, v2, 2009).