The protein encoded by this gene is thought to be a negative regulator of NF-kappa-B mediated transcription. The encoded protein may bind NF-kappa-B complexes and trap them in the cytoplasm, preventing them from entering the nucleus and interacting with the DNA. Phosphorylation of this protein targets it for degradation by the ubiquitination pathway, which frees the NF-kappa-B complexes to enter the nucleus.