PDCD1 and hepatocellular carcinoma: Indeed, NK cells account for ~50% of the lymphocytes in the liver.4 SLAMF7 stimulates NK cell cytotoxicity as both a ligand and a receptor, and the anti-SLAMF7 agent elotuzumab is approved by the FDA for the treatment of multiple myeloma.38 HCC has low cure and survival rates,39 and among the various and complicated HCC etiologies, non-viral HCC, particularly MASH-related HCC, is unresponsive to immunotherapy with anti-PD-1 antibody.17 Therefore, the possibility that TSIs can suppress the immunosuppressive effect of TM4SF5 on NK cells has clinical implications for the treatment of HCC.