1.Develop, test, validate, and standardize novel model system(s)/assays of hepatitis C virus replication and /or infection suitable for the testing of the efficacy of anti-viral agents.2.Improve, standardize, and adapt new assays for determining the activity of compounds against hepatitis C virus.3.Develop, test, validate, and standardize small animal model(s) of hepatitis C virus infection and/or hepatitis C-induced pathogenesis.4.Evaluate compounds against hepatitis C virus infection in vivo