ABL1 and Chronic Eosinophilic Leukemia, Not Otherwise Specified: Other gene fusions: eosinophilia-associated neoplasm can be characterized by rare rearrangements involving FLT3 and ABL1. The most common include ETV6-FLT3 and ETV6-ABL1, which are typically identified in chronic myeloid diseases, such as eosinophilic leukemia and/or in T-ALL leukemia/lymphoma [92,93].