IL18 and Sepsis: Several pro-inflammatory genes commonly expressed during early sepsis were down-regulated in MW2ΔsaeR/S-infected mice compared to MW2-infected mice, including: IFN-γ: -11.27-fold (P≤.05), TNF: -9.37-fold (P>0.10), IL-18: −7.17 (P≤0.01), CD40 ligand: −4.92 (P≤0.01), IL-1β: −4.07 (P≤0.05) and C-reactive protein: −4.43 (P≤0.05) (Tables 1 and S1).