In the periodontal inflammatory microenvironment, lipopolysaccharide (LPS) interacts with monocytes to produce a variety of cytokines that function in classic pathways of periodontitis bone destruction, such as tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6); it also plays important roles in the progression of periodontitis. This evidence concerns the gene TNF and periodontitis.