TNFalpha-IP 8 (tumor necrosis factor, alpha-induced protein 8), also known as NFkB-inducible DED-containing protein (NDED), SCC-S2 or TNF-induced protein GG2-1, is a 198 amino acid cytoplasmic protein induced by NFkB and TNF. The induction of TNFalpha-IP 8 by TNF is dependent on the activation of NFkB. TNFalpha-IP 8 negatively mediates apoptosis and may also play a role in tumor progression. TNFalpha-IP 8 specifically inhibits caspase-8 activity, which results in the inhibition of BID cleavage and caspase-3 activation during TNF-mediated apoptosis. TNFalpha-IP 8 is expressed at high levels in thymus, bone marrow, lymph node, spleen, thyroid, placenta and various tumor tissues, as well as fetal lung, liver and kidney. TNFalpha-IP 8 is present as three isoforms produced by alternative splicing.