PDCD1 and hepatocellular carcinoma: These observations are in contrast with previous reports showing the effectiveness of anti-PD-1 agents in promoting tumour regression in non-NAFLD HCC models [112] and suggest the possibility that in NASH-derived HCCs CD8+/PD-1+ T-cells lack immune-surveillance functions and have instead a tissue-damaging action, which is partially counteracted by PD-1 signalling, thus explaining the unfavourable effects of anti-PD-1 agents on tumour development [41] (Figure 1).