In direct contact coculture system, CD8+ T cells from NCs induced elevated target AGS cell death (17.07 ± 2.81%) when compared with those from GC patients (peripheral: 12.56 ± 2.96%, LSD-t test, P = 0.0039, Fig. 5a; tumor-infiltrating: 12.56 ± 2.96%, LSD-t test, P < 0.0001, Fig. 5a). This evidence concerns the gene CD8A and gastric cancer.