(a-c) Supernatants of whole lung homogenates taken on days 2 and 7 after infection of wild-type mice (WT) and Ripk2 −/− mice with the PR8 virus were analyzed for IL-6 and TNF (day 2; a), IL-18 and IFN-γ (b), and indicated chemokines (c). *P 0.05, **P 0.01 (unpaired two-sided Student's t-test). Data were normalized for total protein (t.p.) from lung homogenates. Data are pooled from three experiments (mean ± s.e.m.; n = 10-12 mice total). 