TNFRSF9

TNFRSF9, tumor necrosis factor receptor superfamily member 9, alias CD137, 4-1BB, is a type I transmembrane protein belonging to the tumor necrosis factor receptor superfamily, which is mainly expressed on the surface of activated T cells, but also in B cells, monocytes, and various transformed cell lines.
TNFRSF9 protein binds to ligand 4-1BBL (TNFSF9), which activates the downstream NF-κB signaling pathway and promotes clonal proliferation, survival and development of T cells. TNFRSF9 plays a critical role in the immune response, especially in enhancing T cell-mediated immune responses and regulating cytotoxic T cell activity.
TNFRSF9 expression is also associated with a variety of diseases, including autoimmune diseases and tumors, and is a potential target for immunotherapy.