Description: The TW4-2F8 monoclonal antibody reacts with human latency associated peptide (LAP, pro-TGF beta 1, LAP/TGF beta 1). Many different cells produce TGF beta and it mediates effects on the proliferation, differentiation and function of many cell types. TGF beta is synthesized as a precursor that contains LAP at the N-terminus and mature TGF beta at the C-terminus. Processing and cleavage of the precursor protein between amino acids 278 and 279 results in the formation of LAP dimers and TGF beta dimers that then non-covalently associate with each other to form the small latent TGF beta complex. LAP is secreted and can be found in the extracellular matrix. In addition, LAP can also be expressed on platelets and activated regulatory T cells. It is believed that this surface-expressed LAP is due to the binding of LAP to GARP (LRRC32), which is a transmembrane protein that is also found at high levels on platelets and activated regulatory T cells.