The discovery of Philadelphia chromosome in chronic myeloid leukemia (CML) followed by the characterization of t(9;22)(q34;q11) with underlying ABL1/BCR gene fusions supported the causative role of chromosomal abnormalities in carcinogenesis and set the foundation for cancer cytogenetics (Mitelman et al., 2007). Here, ABL1 is linked to chronic myelogenous leukemia, BCR-ABL1 positive.