Activated because of the antibiotic rifampicin and many plant metabolites, for example hyperforin, guggulipid, colupulone, and isoflavones. Reaction to precise ligands is species-precise. Activated by naturally occurring steroids, for instance pregnenolone and progesterone. Binds to a response factor from the promoters with the CYP3A4 and ABCB1/MDR