A significantly lower percentage of patients in the early H pylori eradication therapy group with a peptic ulcer history (P = 0.042) used PPIs (P < 0.001), H2-blockers (P < 0.001), COX-2-specific inhibitors (P = 0.013), and ticlopidine (P = 0.021) than did patients in the late H pylori eradication therapy group. Here, PTGS2 is linked to peptic ulcer disease.