XAF1 and gastric cancer: Additionally, IF assays revealed that XAF1 protein expression was lower in the mutated group than in the nonmutated group.<h4>Conclusion</h4>Our study provides evidence that a <i>XAF1</i> mutation (c.454+1372G>A) leads to repressed expression of XAF1 and is associated with a predisposition to GI tumorigenesis, especially in esophageal and gastric cancers.