TGFB1 and influenza: TGFβ has been shown to act as a proviral factor in lung epithelium, where it promotes viral replication, and epithelium-derived TGF beta acts to suppress early IFN beta responses, leading to increased viral burden and pathology [63]; however, during appropriate viral replication control, TGFβ acts as an anti-inflammatory cytokine that limits influenza-induced lung pathology [64].