IL1B and infection: Masp2−/− mice had significantly lower brain levels of interleukin (IL)-1β (median 3.46 vs. 5.33 ng/mg tissue, P = 0.045), IL-10 (1.04 vs. 1.70 ng/mg tissue, P = 0.038), and TNF-α (9.32 vs. 22.58 ng/mg tissue, P = 0.025) compared to WT mice at 30 h after infection (Fig. 2b–d).