– SU-909 (SU909, IKK?-IN-48) is a potent, selective IKK? inhibitor with Ki of 0.08±0.07 uM, 10-20-fold selectivity over IKK? (IC50=1.0±0.28 uM); inhibits FCS-stimulated phosphorylation of p100 in U2OS cells with IC50 of 8.8 uM, inhibits the noncanonical NF-kB pathway without affecting IKK?-dependent IKappa-B? loss in the canonical pathway.