MR analyses revealed that NR0B2 expression is associated with a risk of gastric diseases (NR0B2 vs. gastric cancer, p = 0.006, OR: 0.073, 95%CI: 0.011–0.478; NR0B2 vs. gastric ulcer, p = 0.03, OR: 0.991, 95%CI: 0.984–0.999; NR0B2 vs. other gastritis, p = 0.006, OR:3.82, 95%CI: 1.468–9.942). The gene discussed is NR0B2; the disease is gastric ulcer.