This gene encodes a cytoplasmic protein which specifically colocalizes and interacts with the serine/threonine protein kinase, receptor-interacting protein (RIP). Zinc finger domains of the encoded protein are required for its interaction with RIP and for inhibition of TNF- and IL1-induced NF-kappa B activation pathways. The encoded protein may also function as an E3 ubiquitin-protein ligase which accepts ubiquitin from E2 ubiquitin-conjugating enzymes and transfers it to substrates. Several alternatively spliced transcript variants have been described for this locus but the full-length natures of only some are known. [provided by RefSeq, Jul 2008].