CD4 and Hepatic fibrosis: It was found in clinical studies that anti-PD-1 and anti-CTLA-4 monotherapy could lead to a higher incidence of acute liver injury, and anti-PD-L1 antibodies such as atezolizumab may promote fast progression of liver fibrosis, triggered by acute intrahepatic immunocytes infiltration of CD4+ and CD8+ T-cells principally (Honma et al., 2021).