TNF and infection: Although the expected amount of FliC produced during the course of an OV infection would be small, even minute amounts of bacterial flagellin (≤5 μg/animal) administered to mice by tail vein injection causes global (i.e., in both organs and plasma) elevations of the cytokines TNF, IL-1β, IL-6, and the chemokine MIP-2 (IL-8), as well as changes in the MEK intracellular signaling pathway [84].