Macrophages play an important role in innate immunity for the first line of host defense against microorganisms and are one of the major sources of the destructive cytokines, such as interleukins (IL-1β, IL-6) and tumor necrosis factor (TNF-α), which are critical for the inflammatory response that exacerbates tissue damage in periodontitis [11]. The gene discussed is TNF; the disease is periodontitis.