After stimulated with anti-CD3-mAbs and brefeldin A, inhibited PD-1+ significantly enhanced the production of IFN-γ by tumor-infiltrating CD4+/CD8+ T-cells in patients with GC as compared with FMO control (p = 0.0006, Fig. 4b for CD4+; p = 0.0001, Fig. 4c for CD8+). Here, CD8A is linked to gastric cancer.