Moreover, immune checkpoint inhibitors such as programmed cell death 1 (PD-1), programmed cell death ligand 1 (PD-L1), or cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) are now undergoing clinical trials, and they may open new doors for the treatment of HCC [44]. Here, CTLA4 is linked to hepatocellular carcinoma.