TLR4 and dengue disease: In conferring resistance against DENV invasion, the mosquito Toll signaling pathway activates nuclear factor-kappaB-IkB transcription factor, REL1, thus inducing the expression of antimicrobial peptides (Bian et al., 2005; Waterhouse et al., 2007) that are crucial for the anti-dengue immune responses of A. aegypti (Xi et al., 2008).