PDCD1 and hepatocellular carcinoma: There was a novel investigation into modifying the exosomes to display monoclonal antibodies on the exosome surface to treat epithelial malignancies [97], indicating that we may strengthen the efficacy of ICIs for HCC patients by reprogramming exosomes to display monoclonal antibodies against PD-1, PD-L1, or CTLA-4 on the exosome surface.