CD274 and gastric adenocarcinoma: In conclusion, PD-L1 and PD-L2 expression in primary tumors and matched metastatic lymph nodes, low density of CD8(+) T cells in primary tumors, and PD-1 expression on CD8(+) T cells in primary tumors were unfavorable prognostic factors in patients with stage II/III gastric adenocarcinoma.