CML is a clonal haemopoietic stem cell disorder characterised by a reciprocal translocation between the long arms of chromosomes 9 (ch9) and 22 (ch22), which produce the fusion BCR-ABL1 oncogene. (Apperley, 2015). The gene discussed is ABL1; the disease is chronic myelogenous leukemia, BCR-ABL1 positive.