4. Subjects must be HCV treatment-naïve (i.e., subject has never received a single dose of any approved or investigational anti-HCV medication) or HCV treatment-experienced (subject who has failed prior IFN or pegIFN with or without RBV, or SOF plus RBV with or without pegIFN). GT3 subjects must be HCV treatment-naïve. Previous HCV treatment must have been completed greater than or equal to 2 months prior to Screening.