The multimeric I kappa B kinase (IKK) complex is a key regulator of NF-kappa-B signaling, which is responsible for the phosphorylation of inhibitor kB (IkB). The phosphorylation by IKK triggers K48-linked ubiquitination of IkB leading to proteasomal degradation of IkB, allowing translocation of NFkB factor to the nucleus, where it can activate transcription of a variety of genes participating in the immune and inflammatory response, cell adhesion, growth control, and protection against apoptosis (Alkalay I et al. 1995; Collins T et al. 1995; Kaltschmidt B et al. 2000; Oeckinghaus A and Ghosh S 2009). The IKK complex is composed of the two catalytic subunits, IKKa (IKBKA, IKK1 or CHUK) and IKKb (IKK2 or IKBKB) kinases, and a regulatory subunit, NF-kappa-B essential modulator (NEMO, IKKg or IKBKG). IKBKG (NEMO) associates with the C-termini of unphosphorylated IKKs and promotes the IKK complex activation (Rothwarf DM et al. 1998). The molecular composition and stoichiometry of the IKK complex remains debatable, although the core IKK complex that range from 700 to 900 kDa is thought to consist of an IKBKA:IKBKB heterodimer associated with an IKBKG dimer or higher oligomeric assemblies (DiDonato JA et al. 1997; May J et al. 2002; Tegethoff S et al. 2003; Marienfeld RB et al. 2006; Rushe M et al. 2008).