Many studies have shown that the levels of these cytokines in saliva, GCF, or serum of periodontitis patients with diabetes are higher compared to systematically healthy patients.83, 84, 85, 86 One systematic review reported that even patients with diabetes with better glycaemic control might still have higher GCF levels of IL-1β than healthy individuals.87 The gene discussed is IL1B; the disease is diabetes mellitus.