As we wondered whether IL-17A could be abnormal in patients with IM/DYS, we further measured serum IL-17A in Helicobacter pylori patients with gastric intestinal metaplasia and gastric dysplasia, in non-atrophic gastritis Helicobacter pylori patients without IM/DYS and in healthy controls. The gene discussed is IL17A; the disease is chronic atrophic gastritis.