Toll-like receptors (TLRs) are signaling molecules that recognize different microbial products during infection and serve as an important link between the innate and adaptive immune responses. These proteins act through adaptor molecules such as MyD88 and TIRAP to activate various kinases and transcription factors. TLR11 is one of three mouse TLRs that lack a human ortholog. It is activated specifically by uropathogenic bacteria, and mice lacking TLR11 showed a much greater susceptability to uropathogenic infections, indicating a potentially important role for TLR11 in preventing infections in the urogenital system.