TNF and infection: After binding to the pathogen-sensing system, components of the bacterial cell, including lipopolysaccharide (LPS), through intracellular signaling cascades, activate the release of large numbers of pro-inflammatory cytokines, including tumor necrosis factor (TNF)-α and interleukin (IL)-1β, which in turn recruit leukocytes to the sites of periodontitis, in order to combat infection [5,6].