CD8A and gastric cancer: Recently, Mimura et al. found that PD-L1 expression is mainly controlled by JAK-STAT pathway-associated IFN-γ in GC, and clinical GC samples with PD-L1 expression are strongly positively correlated with CD8 (+) T cells in the stroma as well as IFN-γ expression (Mimura et al., 2018).