5-OxoETE is a polyunsaturated keto acid formed by the oxidation of 5-HETE in human neutrophils by a specific dehydrogenase. It stimulates cytosolic calcium levels in neutrophils with an EC50 value of 2 nM. 5-OxoETE selectively stimulates the migration and degranulation of eosinophils and activates the MAPK pathway in stimulated neutrophils via a specific G protein-coupled receptor.