Firstly, different MPN subtypes are characterized, independently of their mutation status, by different cytokines: macrophage-produced IL-1β for PV; T-cell-produced IL-4, IL-9, IL-26, TGF-β for ET; IL-15 and anti-inflammatory HGF for PMF. Here, TGFB1 is linked to myeloproliferative neoplasm.