Effect of siRNA knockdown on IRF3, IRF5, and IRF7 gene expression. PCR was performed to determine the percent maximum relative gene expression of poly (I-C) stimulated scramble control of IRF3/5/7 genes after siRNA knockdown and 6 h poly (I-C) stimulation followed by quantitative analysis of mRNA. Transfection of siRNA significantly knocked down IRF3, IRF5, and IRF7 gene expression (86% ± 3%, n = 3; 74% ± 6%; n = 3; and 78% ± 4%; n = 3 respectively).