The relationship between ERGPS and mRNA expression levels of immune checkpoint-related genes (PD-L1, PDCD1LG2, PDCD1, TIGIT, TIM-3, CTLA4) commonly used in liver cancer immunotherapy was investigated further, and the results indicated that mRNA expression levels of these immune checkpoint-related genes were elevated in the high-risk group compared to the low-risk group (Figures 7B–G). This evidence concerns the gene PDCD1 and liver cancer.