One patient with CSF3R mutations was observed in MDS, 2 cases in CMML and 4 in other myeloproliferative neoplasia (1 CNL, 1 hypereosinophilia, 1 secondary myelofibrosis MF post-PV and 1 primary MF), accounting for frequencies of 1.1%, 7.4% and 6.7% respectively (Fig. 1). The gene discussed is CSF3R; the disease is myelodysplastic syndrome.