In advanced stages of HBV disease, host genetic factors influence the outcome of HBV infection [7, 10, 11], including HLA-DQ (rs9275319), HLA-DRB1 (rs2647073, rs3997872), STAT4 (rs7574865), C2 (rs9267673), PNPLA3 (rs738408, rs738409), SLC17A2 (rs80215559), HFE (rs1800562) [12, 13] for liver cirrhosis and KIF1B (rs17401966), HLA-DQA1/DRB1 (rs9272105), HLA-DQ (rs9275319), STAT4 (rs7574865) for hepatocellular carcinoma [14–16]. The gene discussed is C2; the disease is hepatocellular carcinoma.