In the immune microenvironment of gastric cancer tissues, the expression level of Tim3 is significantly higher than that in normal gastric mucosa tissues [95, 96], and the expression level of Tim3 was shown to be positively correlated with PD-1/PD-L1 [88], suggesting that Tim3 may have an effect on anti-PD-1/PD-L1 immunotherapy. This evidence concerns the gene PDCD1 and gastric cancer.