The Toll-like receptor (TLR) family in mammal comprises a family of transmembrane proteins characterized by multiple copies of leucine rich repeats in the extracellular domain and IL-1 receptor motif in the cytoplasmic domain. Like its counterparts in Drosophila, TLRs signal through adaptor molecules (1). The TLR family is a phylogenetically conserved mediator of innate immunity that is essential for microbial recognition (2).  TLR12 has been cloned that displays a distinct pattern of expression in macrophages and liver, kidney, and bladder epithelial cells. TLR12 does not respond to known TLR ligands.