CTLA4 and hepatocellular carcinoma: Therefore, ICIs, including anti-PD-1 (pembrolizumab and nivolumab), anti-PD-L1 (durvalumab and atezolizumab), and anti-CTLA-4 (tremelimumab and ipilimumab), are promising agents that can facilitate the proliferation of immune cells and reinforce antitumor immune response by blocking the ligand binding site or inhibiting the expression of PD-1 and CTLA-4 in the treatment of patients with HCC.