This protein is a member of the NF-kappa-B inhibitor family, which contain multiple ankrin repeat domains. The protein is interacts with REL dimers to inhibit NF-kappa-B/REL complexes which are involved in inflammatory responses. The protein moves between the cytoplasm and the nucleus via a nuclear localization signal and CRM1-mediated nuclear export. Mutations in this gene have been found in ectodermal dysplasia anhidrotic with T-cell immunodeficiency autosomal dominant disease.