PDCD1 and hepatocellular carcinoma: Drug-based treatment strategies for HCC are molecular-targeted drugs (MTDs), including tyrosine kinase inhibitors (TKIs) such as by sorafenib (Roskoski, 2019; Roskoski, 2020; Roskoski, 2021; Roskoski, 2022) and immune-checkpoint inhibitors (ICIs) acting on programmed cell death-1/programmed cell death-ligand 1 (PD-1/PD-L1) (Donisi et al., 2020; Giraud et al., 2021).