. IκB kinase (IKK) is an enzyme complex that is upstream of the NFκB signal transduction cascade. NFκB is a transcription factor whose expression is
regulated by the inhibitor of kappa B (IκBα) protein. When the cell is in a basal, non-inflammatory state, IκBα sequesters NFκB in the cytoplasm, rendering the transcription factor inactive. IKK provides another level of regulation by controlling the activity of inhibitory IκBα.