TABLE 3.

Pre-clinical studies with PD-1 immune checkpoints.

Cancer	Number	Immune checkpoints	Treatment	Target	Ref
HCC	71	PD-L1 and PD-1	PD-L1 Ab and PD-1 Ab	CD8+T-cells and Kupffer cells	Li et al. (2016)
HCC	not reported	PD-L1	PD-L1 shRNA	HCC cell lines	Lienlaf et al. (2016)
HCC	59	PD-1	PD-1 antibodies	tumor-infiltrating T-cells	Chang et al. (2017)