According to a recent systematic review and meta-analysis, it was concluded that the salivary biomarkers that have a potential for the diagnosis of periodontal diseases are TNF-α, TNF-β, IL-1α, IL-1β, IL-4, IL-6, IL-8, IL-10, IL-17, IL-32, PGE2, MMP-8, MMP-9, MIP-1α, and TIMP-2. This evidence concerns the gene TNF and periodontal disorder.