PDCD1 and hepatocellular carcinoma: Therefore, in this study, we analyzed the frequency and phenotype of various immune cells in the periphery of HBV-HCC, including T cells, B cells, NK cells, NKT cells, γδ T cells and their subsets, and the expression of immune checkpoints including PD-1, TIGIT, TIM3, and LAG3 in circulating immune cells in HBV-HCC patients.