As in most periodontal diseases, the activity of bacteria in the biofilm, such as Fusobacterium and Streptococcus species, stimulates the host immune response.8 Multiple proinflammatory mediators and their corresponding receptors participate in the process of inflammation, including interleukins (ILs), tumor necrosis-α (TNF-α), matrix metalloproteinases (MMP), etc.9 However, the severity of immune response and the extension of tissue destruction may not be comparable between individuals, even in the presence of similar etiologic factors. Here, TNF is linked to periodontal disorder.