CD8A and hepatocellular carcinoma: To overcome the limitation of the very low-frequency of HBV-specific CD8 T cells in patients with CHB and HBV-related HCC, it is possible to reengineer T cells able to recognize HBV epitopes by TCR gene transfer.14, 25 However, adoptively transferred T cells have been shown to remain susceptible to PD-1-mediated exhaustion in vivo.