Withaferin A strongly elicits IkappaB kinase beta hyperphosphorylation concomitant with potent inhibition of its kinase activity. - Kaileh,M.; Vanden Berghe,W.; Heyerick,A.; Horion,J.; Piette,J.; Libert,C.; De Keukeleire,D.; Essawi,T.; Haegeman,G. (J Biol Chem, 2007)