Assessing the accuracy of diagnostic molecular biomarkers in periodontitis patients, the GCF MMP-8 level was found to have good sensitivity and excellent specificity.8 Previous studies have shown that the MMP-8-saliva levels in periodontitis patients are >3-fold higher compared to healthy controls.17 Similarly, GCF MMP-8 levels correlated with clinical signs of disease activity in patients with chronic periodontitis.8 MMP-8 levels have been found to statistically significantly drop from baseline when a good response to periodontal therapy is determined. The gene discussed is MMP8; the disease is periodontitis.