TNF and infection: Through their pattern recognition receptors, phagocytic cells respond to infection, injury or inflammation by secreting various proinflammatory mediators, including tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β), prostaglandin (PG) E2 as well as the free radicals, nitric oxide (NO) and reactive oxygen/nitrogen species (ROS/RNS) (4).