COPB2 and hepatocellular carcinoma: In order to verify the results of the above bioinformatics analysis, we performed immunohistochemical staining on tumor tissues (n = 20) and matched nontumor tissues (n = 20) from HCC patients; as expected, the results showed that COPB2 was significantly overexpressed in tumor tissues (Figures 1(e) and 1(f), p < 0.0001).