Sensitivities of the Q80K/R+R155K variants to PIs other than simeprevir. wt HCV RNA or the HCV RNA encoding the Q80K+R155K or Q80R+R155K variant in H77S.3/GLuc2A was transfected into Huh-7.5 cells. The medium was replaced with fresh medium containing only DMSO, asunaprevir (A), grazoprevir (B), or paritaprevir (C) at 0.1, 5, 10, 500, or 1,000 nM after 24 h and at 24-h intervals thereafter. The GLuc activity in the medium was determined at 72 h posttransfection. With each NS3/4A PI, the GLuc activity in simeprevir-treated cells was normalized to that in cells treated with DMSO only.