Since the pathogenesis of F/P(+) eosinophilia-associated atypical myeloproliferative neoplasms (Eos-MPN) is similar to that of BCR-Abl(+) chronic myeloid leukemia (CML), the involved signaling mechanisms may also be similar. This evidence concerns the gene ABL1 and chronic myelogenous leukemia, BCR-ABL1 positive.