TNF receptor II (TNFRII or TNFRSF1B), along with the structurally related TNFRI, belong to the TNF receptor superfamily of proteins. TNFRII has a more restricted expression pattern than TNFRI, limited mainly to hematopoietic and immune system cells, whereas TNFRI is thought to be present on all cell types. TNFRII is a high-affinity receptor for TNF-alpha and also binds TNF-beta, but at a lower affinity. Binding to membrane-bound TNF results in effective activation, but while soluble TNF binds to TNFRII, it does not activate its signaling pathway. Signaling through this receptor regulates various biological processes, including cell proliferation, differentiation, apoptosis, lipid metabolism, coagulation, and neurotransmission. The soluble form of TNFRII is capable of inhibiting TNF-alpha-induced activities by acting as a decoy receptor, thereby reducing the inflammatory response.