Regulatory elements of the human microsomal prostaglandin E synthase-1 (mPGES-1) and cyclooxygenase-2 promoters. AP-1 or -2, activator protein-1 or -2; c/EBP, CCAAT/enhancer-binding protein; GR, glucocorticoid receptor; NFκB, nuclear factor κB; PR, progesterone receptor; Sp1, specificity protein-1.