HepG2, HepG2-miR-122 (36 (link)) (obtained from Dr Matthew Evans, Icahn School of Medicine at Mount Sinai), Huh-7.5 and Huh-7.5-ΔmiR-122 (37 (link)) cells (obtained from Dr Charles Rice, Rockefeller University) were maintained in DMEM medium with 10% fetal bovine serum. Sofosbuvir (2′-deoxy-2′-α-fluoro-β-C-methyluridine-5′-monophosphate) was purchased from ChemScene, LLC (Monmouth Junction, NJ). Final dilutions contained 0.1% DMSO. Cell viability was assessed with WST-1 reagent (MilliporeSigma, Burlington, MA) using the manufacturer’s suggested protocol.