In addition, our recent clinicopathological correlation study of PD-L1 and APE1 expression in gastric cancer demonstrated a positive correlation of PD-L1 and APE1 protein expression in cancerous tissue (Qing et al. in press), suggesting that this positive correlation could be due to regulation by a common miRNA regulator, miR-513a-5p. This evidence concerns the gene APEX1 and gastric cancer.