IL21 and infection: Several studies have reported that NWH infection potently induces multiple proinflammatory cytokines and chemokines, with increasing levels of interferon-γ (IFNγ), tumor necrosis factor-α (TNF-α), transforming growth factor β (TGF-β), interleukin (IL) -6, IL-21, and IL-10 all correlated with increasing disease severity and pathogenesis (12–15).