In advanced HCC, immunotherapies have rapidly evolved in recent years, and most of them focused on monoclonal antibodies against CTLA-4 and PD-1 that block immune checkpoints pathways to reactivate the tumor-killing activity of immune cells in the TME (Cho et al., 2017; Seidel et al., 2018). Here, PDCD1 is linked to hepatocellular carcinoma.