PD-1/PD-L1 blocking antibodies are believed to act primarily in TME by re-invigorating pre-exhausted CD8+ T lymphocytes and reviving the immune response against tumor.36 Hence, the distribution of tumor-infiltrating CD8+ T cells with varying stages of exhaustion may have implications for the design of therapeutic strategies as well as for prognosis evaluation. Here, PDCD1 is linked to neoplasm.