IKKε

IKKε (IKBKE) is a non-canonical IκB kinase that functions as a central regulator of innate immune signaling by coordinating antiviral and inflammatory responses through the activation of interferon regulatory factors and downstream type I interferon pathways^[1][2]. Mechanistically, IKKε operates within the TBK1-IKKε-IRF3/IRF7 signaling axis, where it contributes to nucleic acid sensing pathways and promotes transcriptional programs required for host defense and immune adaptation^[1][3]. Beyond antiviral signaling, IKKε also regulates metabolic and inflammatory processes, supporting its emerging role in obesity, diabetes, and related metabolic disorders^[4]. In disease-relevant experimental models, genetic or pharmacological disruption of IKKε activity alters inflammatory homeostasis, and combined impairment of IKKε and TBK1 induces systemic inflammation, myeloid cell expansion, and intestinal pathology in mice, demonstrating an essential role in maintaining tissue integrity and controlling RIPK1-associated inflammatory responses^[5]. Compared with the closely related kinase TBK1, IKKε exhibits both overlapping and distinct biological functions; notably, IKKε can compensate for loss of TBK1 kinase activity in vivo, while specific C-terminal regions required for downstream signaling and type I interferon activation are functionally important in IKKε but not in TBK1^[5][6]. Therefore, the distinction between IKKε and TBK1 is highly relevant for mechanistic studies of innate immunity and inflammation. For experimental applications, small-molecule inhibitors targeting IKKε or the TBK1/IKKε kinase network have been developed and are widely used to investigate inflammatory, metabolic, autoimmune, and cancer-associated signaling pathways, supporting the evaluation of IKKε as a therapeutic target and research tool^[4][7][8].