IDO1 and hepatocellular carcinoma: Since pLVX-HA-HBV-P cells inhibit Jurkat cell function through receptor ligand binding, suggesting that HBV-DNA-Pol may affect the expression of immune checkpoint molecules in HCC cells, we therefore used qRT-PCR to detect the expression of immune checkpoint molecules in both pLVX-HA and pLVX-HA-HBV-P cell lines, including genes encoding PD-L1, CD73, CD47, CD146, CD155, ICAM1, CD74, IDO, and B7H3.