CAY10576 is a thiophenecarbonitrile compound that acts as a potent ATP-competitive inhibitor of IKK-3 (IKK-ε, IC50 = 40 nM) with ~20-fold selectivity over PLK1 and more than 125-fold selectivity over a panel of 9 other commonly studied kinases, including IKK-1/2 (IKK-α/β). Reported to be inactive against cytochrome P450 isozymes (IC50 < 50 μM) 1A2, 2D6, 2C9, and 3A4.