CXCL8 and Helicobacter pylori infectious disease: By contrast, both the protein and mRNA levels of IL-8 were significantly lower after eradication of H. pylori than those before eradication of H. pylori in patients with H. pylori infection and family histories of gastric cancer (P<0.05; Figs 4 and 5), in patients with H. pylori infection and without family histories of gastric cancer (P<0.05; Figs 4 and 5), or in patients with H. pylori infection (P<0.05; Figs 4 and 5).