By binding PD‐L1, a ligand of PD‐1, on tumor cells, the PD‐1/PD‐L1 signaling pathway has been shown to inhibit the activation of T lymphocytes, reduce the secretion of antitumor cytokines, and facilitate tumor immune escape.4, 5, 6, 7. This evidence concerns the gene PDCD1 and neoplasm.