It is important to note that the use of fibrates and statins in the human population for lipid-lowering has not, to our knowledge, enhanced susceptibility to viral disease. This is probably due to the fact that the innate antiviral response to infection, for example expression of the antiviral protein, Mx, is regulated by type I interferons and not by TNF or IL-1 (24) . While TNF has been reported to exert direct antiviral effects against influenza virus in vitro (25) its antiviral effects in vivo are less clear. Administration of neutralizing anti-TNF antibodies during the course of influenza in mice did not increase viral titers, and the infection still resolved (26) . Furthermore, the course of infection of H5N1 influenza virus was not worsened in mice genetically unable to produce TNF (27) . It is therefore unlikely that agents that interfere with expression of pro-inflammatory cytokines such as TNF will enhance susceptibility to influenza, but this remains to be experimentally tested.