15(S)-HEPE is a monohydroxy fatty acid synthesized from EPA by the action of 15-LO. The biosynthesis of 15-HEPE from EPA in guinea pig epidermal enzyme preparations has been documented.{6407} 15(S)-HEPE generated by soybean lipoxygenation of EPA inhibits RBL-1 cell 5-LO with an IC50 value of 28 μM.{6407}