In a larger scale study on the third National Health and Nutrition Examination Survey (NHANES II) dataset, Genco and colleagues showed that serum TNF-α levels were not correlated with the severity of destructive periodontal disease in BMI over 30 kg/m, and proposed the notion that TNF-α mainly contributes to the initial stage of destructive periodontal disease development [56]. The gene discussed is TNF; the disease is periodontal disorder.