RNAi and Transfection The siRNA (sense-strand sequence) IKKα, 5′-AUGACAGAGAAUGAUCAUGUUCUGC -3′; IKKβ, 5′-GCAGCAAGGAGAACAGAGGUUAAUA -3′; IκBα, 5′-GAGCUCCGAGACUUUCGAGGAAAUA -3′; RPS3-3′ UTR, 5′-GGAUGUUGCUCUCUAAAGACC -3′ (Invitrogen). Transient transfection of siRNA and DNA constructs into Jurkat cells and 293T cells was described previously6.