The effectiveness of such therapy depends not only on the ability of immune cells to adequately penetrate the tumor microenvironment but also on the sufficient expression of immune checkpoints within the cancerous tissue. Lately, inhibitors of immune checkpoints (ICIs) aimed at CTLA-4 and PDCD1 have shown promising results in treating patients with HCC [64]. Here, PDCD1 is linked to hepatocellular carcinoma.