In some studies, PD-L1 expression in GC was associated with favorable outcome (PD-L1 out-off value: >10%) [29], while in others, PD-L1 expression and more CD8+ T cell infiltration were related to poorer progression-free survival (PFS) and OS in GC(PD-L1 out-off value: >5% in tumor cell, >1% in immune cell) [30]. This evidence concerns the gene CD8A and gastric cancer.