For the heartburn category (f and a in Figure 3), strong associations with the two gastric mucosa-related factors (serum HP antibody (F4) and serum PG I/II ratio (F5) reflecting atrophic gastritis) observed in digestive drug-free subjects were for the most part not significant in gastric acid suppressant users (Table 2–4). The gene discussed is HP; the disease is chronic atrophic gastritis.