The TME of HCC is composed of immune cells (cytotoxic CD4+ T cells, CD8+ T cells, and NK cells), abundant immunosuppressive cells, such as Tregs, myeloid-derived suppressor cells (MDSCs), tumor-associated macrophages (TAMs), stromal cells, the extracellular matrix (ECM), blood vessels, tumor cells, and lymphatic vessels, which play an important role in tumor survival, proliferation, invasion, and metastasis (34). Here, CD8A is linked to hepatocellular carcinoma.