The innate immune system is armed with a limited set of germline-encoded pattern recognition receptors (PRRs) capable of sensing a tremendous variety of potential pathogens. Among these PRRs, two phylogenetically and structurally highly related Toll-like receptors, TLR7 and TLR8, recognize the same ligand, single-stranded (ss) RNA. Upon stimulation, they both induce the NF-kB and IRF pathways via MyD88, activating multiple immune cells (e.g. T cells), thus bridging the innate and adaptive immune response. Based on these observations, it is tempting to speculate a redundant role of these two receptors, as they also share other functional homologies.