Prior to the availability of IFN-free therapies, in two Phase 2 studies, SVR rates of 81–86% and 67–80%, respectively, were achieved in treatment-naïve and treatment-experienced patients (prior non-responders, partial responders, and relapsers to therapy with PegIFN/RBV) with HCV GT1 infection treated with simeprevir plus PegIFNα/RBV (PILLAR [6] and ASPIRE [9]). The gene discussed is IFNA1; the disease is infection.