TNF and infection: Moreover, a previous study showed that intraperitoneal infection of SS2 could induce a rapid increase of systemic inflammatory factors in mice, including TNF-α, IL-6, IL-12, IFN-γ, IL-1β, CXCL1/KC/GRO-α, CCL2/MCP-1, and CCL5/RANTES, most of which reached a peak after 6 h of infection and subsequently decreased along with the infection [9].