T lymphocytes are the key immune cells in the tumor immune microenvironment, among which CD8+ T cells, CD4+ T cells, and regulatory T lymphocytes (Treg) subsets have received extensive attention in the development and immunotherapy of HCC (Sangro et al., 2021; Du et al., 2024; Wang et al., 2024b). Here, CD8A is linked to hepatocellular carcinoma.