This gene encodes an inhibitor of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kappaB). The encoded protein prevents NF-kappaB-mediated transcription activation by sequestering it in the cytosol. In response to signals that induce NF-kappaB, such as cytokines and growth factors, the encoded protein undergoes phosphorylation, triggering its rapid ubiquitination and proteasomal degradation. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Apr 2015]