The ultimate goal of correlating ETBF isotype with disease progression would be to identify ETBF as an etiological agent, in much the same way that the ability to diagnose exposure to Helicobacter pylori (Hp), by detection of specific serum anti-Hp antibodies and detection of gastric or fecal Hp, was critical to linking Hp to peptic ulcer disease and gastric cancer [33, 34]. The gene discussed is HP; the disease is peptic ulcer disease.