TNF receptors are an family of proteins that consist of, to date, at least 27 members characterized by their repeated cysteine-rich extracellular sequence homology, and include LT receptor, Fas, CD40, the low affinity nerve growth factor receptor, TRAIL receptors, RANK and death or decoy receptors. Many of these members go by multiple names and are activated by specific ligands, however TNF only has the ability to bind two of these receptors which are also activated by LTα.