TLR9 and chronic hepatitis C virus infection: By virtue of their potent secretion of type-1 interferon upon stimulation with synthetic agonists of TLR7 or TLR9, pDCs may be ideal targets for the induction of local, endogenous IFN-α as a novel therapeutic strategy in the treatment of chronic hepatitis C. However, pDCs derived from cHCV patients appear to be profoundly impaired in their ability to produce IFN-α upon in vitro stimulation, although these findings are disputed.