Thus, the aim of the present study was to investigate the influence of nonsurgical periodontal therapy on the levels of four typical proinflammatory cytokines, including IL-1α, -1β, -6 and TNF-α, as well as one anti-inflammatory cytokine, IL-10, in the GCF of patients with chronic periodontitis and no associated chronic pathologies. The gene discussed is IL1A; the disease is periodontitis.