Reconstitution of FLIP reverses the enhanced NF-KB and IRF3 gene expression in FLIP-/- cells in response to cytoplasmic poly(I:C). (A). FLIP+/- (lane1), FLIP-/- (lane 2), and reconstituted FLIP-/- (lane 3) MEFs were subjected to immunoblot analysis with anti-FLIP antibody. (B). FLIP-/- MEFs stably transfected with GFP vector alone or with a vector carrying FLIP-GFP were left untreated, serving as untreated control, or treated with LF/poly(I:C) for 4 hrs and analyzed by RT-PCR for expression of il-6, ifnb or ifna 4 relative to gapdh. *p < 0.05, compared to FLIP-/- MEFs carrying GFP vector. The data are representative of three experiments with similar results.