NF-κB essential modulator (NEMO) is a regulatory subunit within IκB kinase (IKK).IKK is also composed of two unrelated catalytic subunits called IKKα and IKKβ.NEMO is additionally referred to as IKKγ, IKKAP1, or FIP-3. IKK is responsible for activating the transcription factor, NF-κB, which is involved in immune response.NEMO prefers to bind K63-linked or linear polyubiquitin chains.