In 2017, the author of the present study published a systematic review and meta-analysis regarding the circulating leptin and adiponectin levels in the periodontitis population, the results showed elevated serum levels of leptin and decreased serum levels of adiponectin were found in periodontitis patients, and periodontal treatment influenced the circulating leptin and adiponectin [12]. The gene discussed is ADIPOQ; the disease is periodontitis.