– Eicosapentaenoic acid (EPA) is metabolized into epoxyeicosatetraenoic acids (EpETE) by multiple cytochrome P450 isoforms. The predominant compound of this epoxygenase pathway, (±)17(18)-EpETE, induces relaxation in vascular and airway smooth muscles through its action on large conductance Ca2+-activated K+ (BKCa) channels, specifically by binding to the BKα channel subunits. Another notable epoxygenase pathway derivative, (±)11(12)-EpETE, also generated from EPA via CYP450 activity in both in vitro and in vivo studies, has biological and physiological roles that are yet to be fully elucidated.