Immunological parameters important in carcinogenesis and in subsequent HCC development differ depending on the tumor-triggering factors – high values of Treg and CD8+ resident memory T cells have been observed in HBV-related HCCs, whereas in non-viral-related HCCs a significantly higher percentage of CD244+ NK cells has been observed, as well as CD8+ T cells expressing Tim-3. This evidence concerns the gene CD8A and hepatocellular carcinoma.