The nuclear IκB family of proteins controls gene regulation and immune homeostasis

• NF-κB is an important transcription factor controlling gene regulation and immune homeostasis.
• Inhibitory IκB family proteins can control gene regulation independently of NF-κB.
• Nuclear IκB family proteins interact with NF-κB and alter its transcriptional activity.

The inhibitory IκB family of proteins is subdivided into two groups based on protein localization in the cytoplasm or in the nucleus. These proteins interact with NF-κB, a major transcription factor regulating the expression of many inflammatory cytokines, by modulating its transcriptional activity. However, nuclear IκB family proteins not only interact with NF-κB to change its transcriptional activity, but they also bind to chromatin and control gene expression. This review provides an overview of nuclear IκB family proteins and their role in immune homeostasis.