On the other hand, it has been found that the salivary levels of IL-1β, IL-6, and matrix metalloproteinase-8 (MMP-8) are significantly elevated in patients with periodontitis compared to healthy people, so it has been proposed that the elevation of these three salivary biomarkers associated with inflammatory and destructive processes may constitute indicators of the severity of periodontitis [12]. The gene discussed is MMP8; the disease is periodontitis.