Objective:Study on the expression of Fas and Fas ligand (FasL) in gastric cancer and its possible significance.Methods:Fifty-eight paraffin-embedded gastric cancer tissues and twenty-six non-cancer tissues were tested for the expression of Fas and FasL protein by immunohistochemistry.Results:The positive rate of Fas in cancer cells of gastric cancer tissues was significantly lower than that in gastric epithelial cells of the control tissues(19.0% and 61.5%,respectively;?~2=14.918;P=0.000).The positive rate of FasL showed no significant difference between cancer cells of gastric cancer tissues and gastric epithelial cells of the control tissues(63.8% and 53.8%,respectively).Conclusion:The Fas-FasL system is unbalanced.It may be related to the carcinogenesis of gastric epithelial cells and might be responsible for the immune excape of these cells.