Prominent examples include BCR-ABL in chronic myelogenous leukemia [4] with the development of Gleevec as a paradigm for targeted therapy [5], frequent gene fusion TMPRSS2-ERG in prostate cancer [6], and the rapid targeting of ALK gene fusion products with crizotinib after the discovery of EML4-ALK in lung cancer [7, 8]. The gene discussed is ABL1; the disease is chronic myelogenous leukemia, BCR-ABL1 positive.