ABL1 and chronic myelogenous leukemia, BCR-ABL1 positive: Chronic myelogenous leukemia (CML) is a malignant disorder of hematopoietic stem cells that arises from reciprocal translocation between the BCR gene on chromosome 22 and the ABL gene on chromosome 9, t (9;22) (q34;q11), called Philadelphia chromosome [1, 2].