In a study of Asian HCC patients treated with a single PD-1 immunoagent such as nivolumab, pembrolizumab, or camrelizumab, the objective response rate (ORR) was found to be only approximately 15%, suggesting that the complex immunosuppressive microenvironment of HCC leads to ICIs evasion by unknown mechanisms (5, 9, 10). Here, PDCD1 is linked to hepatocellular carcinoma.