The results showed that the mRNA expressions of seven genes in both TCGA and ICGC sets were significantly different between HCC samples and non-tumor samples, including six genes (CST2, EPHB6, MAGEA6, SEMA6A, SLC2A5, and SLCO2A1), and were highly expressed in HCC samples and one gene (PDZD4) expressed low in HCC samples (Figure 6). This evidence concerns the gene PDZD4 and hepatocellular carcinoma.