ABL1 and chronic myelogenous leukemia, BCR-ABL1 positive: BCR-ABL1, the oncogenic driver of chronic myeloid leukemia (CML), results from a balanced translocation, t(9;22)(q34;q11.2), involving a fusion of the Abelson gene (ABL) from chromosome 9q34 with the breakpoint cluster region (BCR) gene on chromosome 22q11.2 [1].