Knock-out of Abl leads to developmental lethality (Koleske et al., 1998), and fusion with the breakpoint cluster region gene from chromosome 22 yielding the BCR-Abl oncogene de-regulates kinase activity and is the main cause of chronic myelogenous leukemia (Greuber et al., 2013). The gene discussed is ABL1; the disease is chronic myelogenous leukemia, BCR-ABL1 positive.