IL1B and infection: We found that FIP in WT mice caused widespread increases in both pro- and anti-inflammatory mediators (including IL-1β, IL-6, TNFα, KC, and IL-10), concomitant with increased infiltration of in CD11b+ F4/80+ Ly6c[high]+ cells—a subset of macrophages recruited to sites of infection where they phagocytose pathogens and induce local proinflammatory cytokine production [29,30,31,32].