CST1 and periodontitis: In another study, an increase in IL-3, IL-4, IL-5, blood albumin, alpha-amylase, and a decrease in cystatin-1 levels were reported in patients with chronic periodontitis.15 Many identified biomarkers also increase in other inflammatory conditions.16 Additionally, these biomarkers may be linked to infection or collagen and bone destruction, which often manifest later in disease progression.17 Hence, the critical point is to find an appropriate specific biomarker.