JAK2 and Chronic Eosinophilic Leukemia, Not Otherwise Specified: Currently, cases with rearrangements of ABL1, FLT3 and JAK2, with the exception of PCM1-JAK2, are also classified as CEL, NOS even though they show similarities and often indistinguishable clinical features to the category of “myeloid/lymphoid neoplasms with eosinophilia and fusion genes”, indicating that these cases might be classified differently in the future [135,143].