Mammalian IAP Family Genes encode conserved Inhibitors of Apoptosis Proteins with an N-terminal domain containing 1-3 repeats of a 65-70-aa Cys- and His-rich BIR motif and often a zinc-binding RING finger. Some IAPs inhibit apoptosis by regulating ICE-like protease activation signals and/or inhibit serum deprivation-induced apoptosis. Some IAP proteins may bind to TRAF1 and TRAF2. IAP proteins are frequently over expressed in cancers and associated with resistance to therapy. (NCI) [ ]