It was evidence by a laboratory study that smoking could increase the apoptosis in the rat gastric mucosa by an increase in XO activity [29], and alcohol could also exert influence on acid secretion, gastric emptying, and certain acid-related diseases, such as gastritis accompanied with damage of the gastric mucosa, and the following inflammatory reaction will in turn promote gastric cell proliferation and differentiation [30]. The gene discussed is XDH; the disease is gastritis.