HLA-F and hepatocellular carcinoma: The mean survival time of the HLA-F-positive HCC patients was 33.0 months [95% confidence interval (CI), 25.1–40.8 months], which was significantly shorter than that of the HLA-F-negative HCC patients [44.2 months (95% CI, 37.7–50.7 months)] (P=0.040; Fig. 2).