When administered from the beginning of influenza infection, recombinant IL-27 increased the severity of weight loss and impaired viral clearance, likely by interfering with innate immunity.140 Similarly, IL-27 was identified as a factor underlying impaired clearance of respiratory Pseudomonas aeruginosa infection in a murine model of sepsis, in part by suppressing the antibacterial activity of AMs.146 Timely and measured activity of IL-27 is therefore critical during respiratory infection, to limit immunopathology without compromising pathogen clearance. This evidence concerns the gene IL27 and influenza.