CD4 and chronic hepatitis C virus infection: In our study, there was a significant decrease of Tregs and PD-1 expressing CD8+ T-cells in chronic hepatitis C patients at 12 weeks after treatment compared with their baseline levels, indicating that IFN/RBV treatment could restore HCV-specific T-cells response by reducing circulating CD4+CD25+FoxP3+ Tregs and PD-1 expressing CD8+ T-cells.