ABL1 and chronic myelogenous leukemia, BCR-ABL1 positive: Chronic myeloid leukaemia (CML) is a myeloproliferative disease associated with the presence of Philadelphia (Ph) chromosome which results from a reciprocal chromosomal translocation, t(9; 22) (q34; q11), which leads to the formation of constitutively expressing BCR::ABL tyrosine kinase fusion protein [1].