FIP1L1 and Chronic Eosinophilic Leukemia, Not Otherwise Specified: Similar results have been obtained by Sadovnik et al., who demonstrated that ponatinib is a potent antiproliferative agent of neoplastic eosinophils (EOL-1 cells) carrying the fusion protein FIP1L1-PDGFRα, which has been detected in CEL patients [28].