In contrast, both the protein and mRNA levels of IL-8 were significantly elevated in patients with H. pylori infection and no family histories of gastric cancer than those without both H. pylori infection and family histories of gastric cancer (P<0.05; Figs 2 and 3), and they were also significantly higher in patients with H. pylori infection than those without H. pylori infection (P<0.05; Figs 2 and 3). The gene discussed is CXCL8; the disease is gastric cancer.