In vitro evaluation of efavirenz. Effect of efavirenz on transgene (A) DNA expression, (B) RNA expression, and (C) the ratio of transgene RNA/DNA. (D) Effect of efavirenz and AAV on cytotoxicity. ∗P <.05, ∗∗P < .01, ∗∗∗P < .001, ∗∗∗∗P < .0001 using a 2-way ANOVA followed by a Dunnett’s multiple comparisons test. In panels A–C, all samples were treated with valoctocogene roxaparvovec. In panel D, samples treated with AAV received valoctocogene roxaparvovec, and samples not treated with AAV received a vehicle control. AAV, adeno-associated virus; ANOVA, analysis of variance; C_max, maximum plasma concentration; FVIII-SQ, factor VIII SQ-variant; hrs, hours; RPLPO, housekeeping gene for normalizing transcript expression.