RNAi is active in WNV infected cells. RNAi of influenza M2 gene in cells that replicate WNV RNA. Huh7.5, Huh7.5-Rep, and WNV infected Huh7.5 cells (8 hours post infection) were transfected with pCM2 and Cap or M2 siRNA as described in Materials and Methods. 24 hours later cells were processed by flow cytometry for M2 expression using antibody 14C2. The percentage of M2 inhibition was calculated according to the following formula: (1 – (% M2 expression of siRNA-transfected cells / % M2 expression in cells transfected with transfection vehicle only) × 100). The results are an average of three independent experiments and error bars indicate standard error of the mean.