Immunohistochemical staining showed a significant difference in PD-L1 expression level between normal liver tissue and liver cancer tissue (Figure 10B; p = 0.001) from the HPA dataset (http://www.proteinatlas.org/) and HCC tissues from patients in the high-risk group compared to the low-risk group in the TCGA cohort (Figure 10C;p = 0.019). This evidence concerns the gene CD274 and hepatocellular carcinoma.