PDCD1 and gastric adenocarcinoma: We retrospectively detected the expression patterns of PD-L1 and PD-L2 in primary tumors and metastatic lymph nodes, the density of CD8(+) T cells in primary tumors, and the expression of PD-1 on CD8(+) T cells from patients with gastric adenocarcinoma, and determined their associations with clinicopathologic features and patient survival.