TNF and influenza: On the other hand, poly (I:C), administered intranasally in aged mice, has recently been shown to induce the protection against lethal respiratory virus infections, without any side effects, by up-regulating the expression of IFN-β, IFN-γ, IL-1β, and tumor necrosis factor (TNF) in the lungs, indicating the potential applicability of poly (I:C) as a prophylactic agent in aged individuals with risk factors for severe acute respiratory syndrome coronavirus (SARS-CoV) or influenza A virus (IAV) infections [35].