For instance, by combining anti-PD-L1/PD-1 and cytotoxic T lymphocyte antigen 4 (CTLA-4) monoclonal antibodies (mAbs) with anti-vascular endothelial growth factor (VEGF) bevacizumab, the median survival of liver cancer patients can reach 19 months, bringing new hope to the clinical treatment of liver cancer (Llovet et al., 2021a; Llovet et al., 2018; Finn et al., 2020; Qin et al., 2021). This evidence concerns the gene PDCD1 and liver cancer.