PSMD4 and hepatocellular carcinoma: As the figure showed (Figure 4), RPN2 (Area = 0.818 and p < 0.00011), RPN3 (Area = 0.728 and p < 0.0001), RPN6 (Area = 0.704 and p < 0.0001), RPN9 (Area = 0.650 and p < 0.0001), RPN10 (Area = 0.880 and p < 0.0001), and RPN11 (Area = 0.815 and p < 0.0001) were all helpful for HCC diagnosis.