20-HETE is a major biologically active CYP450 metabolite of arachidonic acid in the kidney and liver. It regulates renal vascular and tubular functions as well as vascular tone in the cerebral circulation.{12466,12470,12468,12467,9023} HET0016 is an inhibitor of 20-HETE formation in human renal microsomes with an IC50 of 8.9 nM, selectively inhibiting CYP4A and 4F isoforms.{8946,12469} HET0016 inhibits CYP2C9, CYP2D6, and CYP3A4, enzymes important in drug metabolism, significantly less effectively with IC50 values in the μM range. The IC50 values for inhibition of COX and epoxyeicosatrienoic acids (EETs) formation are 2.3 and 2.8 μM, respectively.{8946}