15(S)-HpETE is a monohydroperoxy polyunsaturated fatty acid (PUFA) produced by the action of 15-lipoxygenase (15-LO) on arachidonic acid. It is either metabolized to 14,15-leukotriene A4 or reduced to 15(S)-HETE by peroxidases. 15(S)-HpETE mediates a number of biological functions including the induction of c-fos and c-jun, and activation of AP-1. 15(S)-HpETE inhibits prostacyclin synthesis in porcine aortic microsomes and bovine endothelial cells, and can cause the suicide inactivation of porcine 12-LO.