Tumor necrosis factor receptor 1 (TNF-R1) is also known as Tumor necrosis factor receptor superfamily member 1A (TNFRSF1A), TNFAR, CD antigen CD120a, which belongs to the tumor necrosis factor receptor superfamily. TNF-R1 contains one death domain and four TNFR-Cys repeats. TNF-R1 is the receptor of TNFSF2 / TNF-alpha and homotrimeric TNFSF1 / lymphotoxin - alpha. The adapter molecule FADD recruits caspase-8 to the activated receptor. The resulting death-inducing signaling complex (DISC) performs caspase-8 proteolytic activation which initiates the subsequent cascade of caspases (aspartate-specific cysteine proteases) mediating apoptosis. TNF-R1 contributes to the induction of non - cytocidal TNF effects including anti-viral state and activation of the acid sphingomyelinase. Defects in TNFRSF1A are the cause of familial hibernian fever (FHF).