Both the World Health Organization (WHO) and the International Consensus Classification (ICC) have updated the former category of “Myeloid/Lymphoid Neoplasms Associated with Eosinophilia and Rearrangement of PDGFRA, PDGFRB, FGFR1, or PCM1::JAK2”. This evidence concerns the gene FGFR1 and Increased total eosinophil count.