Ten human homologs of TLRs (TLR1-10) have been described. TLR8 gene contains three exons, two of which have coding function. TLR8 cDNA codes for a protein of approximate molecular weight of 120 kDa (4,5). 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. Like TLR7, TLR8 is localized to endosomal or lysosomal compartments and stimulates the innate immune response after activation by guanosine- and uridine-rich single-stranded RNA. Human but not murine TLR8 confers responsiveness to the antiviral compound R-848. The protein encoded by this gene is a member of the Toll-like receptor (TLR) family which plays a fundamental role in pathogen recognition and activation of innate immunity. TLRs are highly conserved from Drosophila to humans and share structural and functional similarities. They recognize pathogen-associated molecular patterns (PAMPs) that are expressed on infectious agents, and mediate the production of cytokines necessary for the development of effective immunity. The various TLRs exhibit different patterns of expression. This gene is predominantly expressed in lung and peripheral blood leukocytes, and lies in close proximity to another family member, TLR7, on chromosome X.