Toll-like receptor 3 (TLR3) also known as CD283 (cluster of differentiation 283) is a protein that in humans is encoded by the TLR3 gene.[5] TLR3 is a member of the toll-like receptor family of pattern recognition receptors of the innate immune system. TLR3 recognizes double-stranded RNA in endosomes, which is a common feature of viral genomes internalised by macrophages and dendritic cells.