MSH2 and gastric cancer: For example, the NCCN recognizes risk factors that include male sex, older age, MLH1 or MSH2 pathogenic variant, first-degree relative with gastric cancer, Asian ethnicity, residing or immigrating from countries with high incidence of gastric cancer, and a history of chronic autoimmune gastritis, gastric intestinal metaplasia, or gastric adenomas [7], but the American College of Gastroenterology (ACG) recommends risk stratification based on family history alone [18].