TNF-α is an important cytokine produced by numerous cell types including neutrophils, activated lymphoctyes, macrophages and NK cells. It plays a critical role in inflammatory responses and in apoptosis. The two receptors for TNF-α, TNF-R1 and TNF-R2 can mediate distinct cellular responses. In most cases cytotoxicity elicited by TNF has been reported to act throught TNF-R1. TNF-R1 shares a motif coined the “death domain” with FAS and three structurally unrelated signaling proteins, TRADD, FADD and RIP. This “death domain” is required for transduction of the apoptotic signal .
