The I kappa B kinase (IKK) complex is tripartite and contains IKK gamma but not IKAP as a regular component - Krappmann,D.; Hatada,E.N.; Tegethoff,S.; Li,J.; Klippel,A.; Giese,K.; Baeuerle,P.A.; Scheidereit,C. (J Biol Chem, 2000)