ABL1 and chronic myelogenous leukemia, BCR-ABL1 positive: Amongst the different types of leukemias, chronic myelogenous leukemia (CML) is a clonal malignancy of the hematopoietic stem cells that arises from a 9; 22 chromosomal translocation which fuses the ABL proto-oncogene to the BCR gene encoding the fusion protein p210Bcr-Abl[1], [2].