PDCD1 and cancer: eEF2K expression could predict clinical response rate to anti-PD-1/PD-L1 therapy in patients with cancer, and combinational treatment of eEF2K inhibitors can enhance the efficacy of PD-1/PD-L1 blockade and increase the tumor-infiltrating cytotoxic CD8+ T cell population in the tumor tissues, providing a strong rationale to develop a novel combination therapeutic strategy.