We found that the levels of CD3+, CD4+, CD19+ T cells and NK cells in peripheral blood samples all tended to be reduced in high-risk HCC patients (the case group), whereas the level of CD8+ cells was greater in the case group than in the control group, suggesting that HBV infection alters the proportions of the peripheral blood lymphocyte subsets. The gene discussed is CD8A; the disease is hepatocellular carcinoma.