The TL2.1 monoclonal antibody specifically reacts with human CD282, the Toll-like receptor 2 (TLR2). It is a type I transmembrane signaling receptor containing IL-1 receptor like intracellular domain and leucine-rich repeats (LRR) in the extracellular domain. CD282 is expressed on peripheral blood monocytes and is involved distinguishing bacterial lipoproteins. The TL2.1 antibody blocks the receptor and immunoprecipitates TLR2 from human mammary epithelial cells (HMEC) and peripheral blood mononuclear cells (PBMC).