Tumor necrosis factor receptor superfamily member 1A (UniProt P19438; also known as CD120a, p55, p60, TNF-R1, TNF-RI, TNFR-I, Tumor necrosis factor-alpha receptor, Tumor necrosis factor receptor type 1) is encoded by the TNFRSF1A (also known as FPF, MS5, TNFAR, TNFAR55, TNFAR60, TNFR1) gene (Gene ID 7132) in human. It functions as a receptor for TNFSF2/TNF-alpha and homotrimeric TNFSF1/lymphotoxin-alpha. Upon activation, TNFalpha receptor mediates apoptotic, anti-viral, and other cellular signaling events. Binding of TNF-alpha to the extracellular domain of TNF receptor leads to homotrimerization. Proteolytic cleavage results in the relese of Tumor necrosis factor-binding protein 1 (TBP1). Defects in TNF receptor cause tumor necrosis factor receptor-associated periodic syndrome (TRAPS), a hereditary periodic fever syndrome characterized by recurrent fever, abdominal pain, localized tender skin lesions and myalgia.