Abbreviations: ET, essential thrombocythemia; PV, polycythemia vera; MF, myelofibrosis; MPN, myeloproliferative neoplasm; Peg-IFNα, pegylated interferon alfa; Ropeg-IFNα, ropeginterferon alfa-2b; HU, hydroxyurea; RUX, ruxolitinib; CHR, complete hematologic response; MR, molecular response; BM, bone marrow. This evidence concerns the gene IFNA1 and acquired polycythemia vera.