IL1B and myeloproliferative disorder: However, IFN-α also represses the expression of cytokines and receptors that do not signal via JAK/STAT, notably IL-1β, a major pro-inflammatory cytokine, as well as others that facilitate the survival of MPN progenitors, such as IL-11, hepatocyte growth factor (HGF) and its receptor, c-MET, and tumor growth factors β (TGF-β) [24,25].