TLR2, also known as CD282, is a member of the Toll-like receptor (TLR) family. TLRs are highly conserved from Drosophila to humans and share structural and functional similarities. They play a fundamental role in pathogen recognition and activation of innate immunity. 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. TLR2 contains 14 LRR (leucine-rich) repeats and 1 TIR domain. TLR2 gene is expressed most abundantly in peripheral blood leukocytes, and mediates host response to Gram-positive bacteria and yeast via stimulation of NF-kappaB. CD282 cooperates with LY96 to mediate the innate immune response to bacterial lipoproteins and other microbial cell wall components. It also cooperates with TLR1 to mediate the innate immune response to bacterial lipoproteins or lipopeptides. CD282 acts via MYD88 and TRAF6, leading to NF-kappa-B activation, cytokine secretion and the inflammatory response. It may also promote apoptosis in response to lipoproteins.