Catalyzes erythromycin N-demethylation, nifedipine oxidation and testosterone 6 beta-hydroxylation. an organic molecule + O2 + reduced [NADPH--hemoprotein reductase] = an alcohol + H(+) + H2O + oxidized [NADPH--hemoprotein reductase] Highly expressed in liver. By dexamethasone. Belongs to the cytochrome P450 family.