c-Abl is normally maintained in its inactive state in the cell; however, in patients with Chronic Myelogenous Leukemia (CML), the gene encoding c-Abl is fused with the breakpoint cluster region (BCR) gene, resulting in the formation of the fusion protein BCR–Abl. This evidence concerns the gene ABL1 and chronic myelogenous leukemia, BCR-ABL1 positive.