ABL1 and chronic myelogenous leukemia, BCR-ABL1 positive: For example, its clever use recently led to the surprising finding that myeloma cells may harbor kinase-activating fusion genes (Cleynen et al., 2017; Morgan et al., 2018) analogous to the BCR-ABL1 fusion seen in t(9;22)+ chronic myeloid leukemia (CML).