Drugs which result in intracellular enrichment of specific TKIs may improve TKI therapy in the 1028385-32-1 future. The IKK family of kinases consists of four family members, the canonical IKKa and IKKb, as well as two noncanonical family members, IKKe and TBK1. Together, this family of kinases regulates a myriad of critical cellular processes including inflammation, survival, proliferation, senescence, and 474-58-8 structure autophagy. Consistent with these numerous functions, aberrant IKK signaling can result in susceptibility to diseases such as inflammatory disorders and cancer. The canonical IKK complex, which consists of IKKa, IKKb, and a regulatory subunit, NEMO, is a point of convergence for a variety of stimuli. Upon activation, the canonical IKKs, primarily IKKb, phosphorylate IkBa, the inhibitor of NF-kB, which promotes the ubiquitination and degradation of IkBa. The transcription factor NF-kB is then freed to accumulate in the nucleus and activate the transcription of a number of target genes involved in inflammatory and stress responses. In contrast to the canonical IKKs, IKKe and TBK1 are activated by a smaller subset of inflammatory stimuli, and are especially critical for antiviral responses. These kinases phosphorylate and activate the transcription factors IRF3, IRF7, and STAT1, promoting a Type 1 interferon response. These kinases also activate NF-kB, but the mechanism by which this occurs in unclear since they do not phosphorylate both of the serines on IkBa which are required for IkBa degradation. IKKe and TBK1 can also promote oncogenesis. For example, IKKe is overexpressed in some breast and ovarian cancers, and TBK1 was recently shown to be important for Ras-induced cell transformation. In spite of the important role these kinases play in both inflammatory and oncogenic signaling, few inhibitors have been identified. BX-795, a small molecule inhibitor of 3- phosphoinositide-dependent protein kinase 1, inhibits both IKKe and TBK1 at low nanomolar concentrations in vitro. However, BX- 795 lacks selectivity as 16 out of 76 tested kinases were inhibited by BX-795 in the nM range. It was also recently shown that a series of azabenzimidazole derivatives inhibits these kinases in the low nM range, but 6 of 79 kinases tested using one of these compounds were inh
