In PV, patients increased levels of IL-1RA, IL-4, IL-5, IL-6, IL-7, IL-8, IL-10, IL-12, IL- 13, IFN-γ, GM-CSF, MCP-1, MIP-1α, MIP-1β, HGF, IP-10, MIG, MCP-1, PDGF, TNF-α, IFN-γ and VEGF were measured [65,66,67]. The gene discussed is IL4; the disease is acquired polycythemia vera.