PDCD1 and hepatocellular carcinoma: The first results of studies evaluating anti-PD-1/PD-L1 monotherapies as post-sorafenib second-line treatment in advanced HCC appeared promising for durvalumab (anti-PD-L1), pembrolizumab (anti-PD-1), and cemiplimab (anti-PD-1), while nivolumab (anti-PD-1) could be used first- or second-line.