However, some studies have shown that tumor-infiltrating CD3, CD4, and CD8 T cells in HCC patients were not related to OS and DFS after resection, whereas high-density cytotoxic CD8 T cells (CTL) and low-density regulatory T cells (Tregs) were independent prognostic factors for improving OS and DFS (20). The gene discussed is CD8A; the disease is hepatocellular carcinoma.