Goat anti Human CD137 antibody specifically recognizes human CD137, otherwise known as 4-1BB ligand receptor, a type I transmembrane glycoprotein and member of the tumour necrosis factor receptor superfamily, predominantly expressed by activated T cells, which acts as a receptor for 4-1BB ligand (4-1BBL).Interaction between CD137 and 4-1BBL, acts as a co-stimulatory signal for T cell activation and expansion, and is involved in the generation of cytotoxic T cells (Tc) and in the process of antigen presentation. CD137 also binds to the adaptor proteins TRAF1, 2 and 3 to act as a signal transducer of NF-kappaB activation.