PDCD1 and hepatocellular carcinoma: The major findings of this study include: (1) durvalumab is effective in anti-PD-1 refractory HCC; (2) a prior response to anti-PD-1 predicts the response and outcomes to durvalumab; (3) the irAEs from prior anti-PD-1 therapy showed no association with subsequent irAEs from durvalumab.