PDCD1 and gastric cancer: In patients with Stage II GC, we found that ACT successfully prolonged OS in patients with PD-1+CD8+ T cells high infiltration (P = 0.019, HR = 0.36; Fig. 3b), while no survival benefit was observed in patients with low PD-1+CD8+ T cells infiltration (P = 0.34, HR = 0.59; Fig. 3b).