The rs1800629 consists of a G→A substitution at position 308 in the promoter region of TNF -α and is related to higher frequency of gene expression and higher levels of circulating cytokine, being previously associated with susceptibility to chronic periodontitis and diabetes mellitus type II.24 According to a review by El-Tahan, Ghoneim, and El-Mashad43 (2016) TNF -α has several reported SNPs in its promoter region that are mostly studied in the context of autoimmune diseases and act in either up or downregulation of gene expression. The gene discussed is TNF; the disease is periodontitis.