Recombinant Human 4-1BB/TNFRSF9 Protein (His Tag)(Active)

Tumor necrosis factor receptor superfamily member 9(TNFRSF9); also known as CD137 and 4-1BB; is an inducible T cell surface protein belonging to the tumor necrosis factor receptor superfamily. It is a single-pass type I membrane protein which contains 4 TNFR-Cys repeats. The human and mouse proteins share 60% amino acid sequence identity. CD137 is expressed by mesenchymal cells; including endothelial cells; chondrocytes; and cells of the central nervous system. CD137 is also broadly expressed by cells of the human immune system; is broadly expressed by cells of the human immune system; including activated CD8+ and CD4+ T cells; activated natural killer (NK) cells; follicular dendritic cells (FDCs) and monocytes. CD137 has diverse roles in the immune response; the one key function is to promote the survival of both T cells and dendritic cells by binding the cognate ligand CD137L (4-1BBL).