A cell-permeable synthetic peptide NEMO-binding domain peptide (NBD peptide) corresponding to the NEMO amino-terminal alpha-helical region is shown to block TNF-alpha-induced NF-kB activation. The interaction of IKgammaNEMO with the IKK complex is vital for the activation of the IKK complex and the subsequent activation of NF-kB. Synonym: IKKgamma NBD Inhibitory Peptide