IRF7 and severe acute respiratory syndrome: PP1 was reported to have a function in antiviral innate immunity through the ablation of IKKε-stimulated IRF7 phosphorylation, and it dramatically attenuated IRF7 transcriptional activity that mediated IFNα production in host immune responses.225 PP1 also promoted lung inflammation through TNFα signaling in SARS-CoV infections, whereas its inhibitory subunit Kepi protected against SARS-CoV pathogenesis.226