The monoclonal antibody 3C10C5 reacts with human TLR-10, which is a type I transmembrane glycoprotein that consist of an extracellular domain, a single transmembrane segment and a cytoplasmic Toll/interleukin (IL)-1 receptor domain and has an apparent molecular mass ofapproximately 94kDa. In total humans possess 10 TLR family members (1–10). The TLR 10, 1, and 6 genes are tandemly arranged and seem to have arisen from duplication events. In accordance with their role in host defense, monocytes/macrophages express most TLRs, whereas the expression of individual TLRs in dendritic cells depends upon their subtype. The microbial agonists for TLRs include a wide variety of structures such as nucleic acids from bacteria and viruses, as well as outer membrane components of bacteria, fungi, and protozoan organisms.Despite extensive research on the TLRs, human TLR10 has remained an orphan receptor without a known agonist or function. Although recent studies have shown that the putative ligands includedi- andtriacetylated lipopeptides as can be found in bacteria. Variations in the TLR10 gene have been associated with several diseases such as papillary thyroid carcinoma, urothelial bladder cancer, and Crohn’s disease. The monocalonal antibody 3C10C5 is suitable for immunoassay and flow cytometry.