To further investigate the effect of rm-APC treatment on the inflammatory response in severe influenza, we determined pulmonary levels of various cytokines (TNF-α, IL-1β, IL-6, IL-10, IL-12p70, IFN-γ) and chemokines (KC, MIP-2) in lung homogenates obtained 48 and 96 hours after infection. This evidence concerns the gene IL1B and infection.