NFKB1 and Cushing syndrome due to macronodular adrenal hyperplasia: Although glucocorticoids are know to activate the pathway by opposing the suppression of the transcription of proteasome α-subunits by nuclear factor-κB (NF-κB) (Du et al, 2000) other factors may be involved, since chronic excessive glucocorticoid production, as occurs in Cushing's syndrome, does not increase proteasome expression (Ralliere et al, 1997).