Epoxygenase is an enzyme that produces hydroxyeicosatetraenoic acids (HETEs) and epoxyeicosatrienoic acids (EETs) from arachidonic acid, causing effects such as cell proliferation and decrease in cyclooxygenase activity. 
Hydroxyeicosatetraenoic acids cause:
- In mononuclear leukocytes: Cell proliferation, calcium release from intracellular stores and decreased TNF production. 
- Suggested to destruct beta cells, contributing to type 1 diabetes 
- In endothelial cells: Decreased release of fibrinolytic factors and decrease binding of antithrombin
- Cell proliferation and migration of vascular smooth muscle cells, suggesting contribution to atherosclerosis.
- Vasoconstriction, increased myogenic mechanism sensitivity in renal and cerebral arteries.
Generally, EETs cause:
- Calcium release from intracellular stores
- Increased sodium-hydrogen antiporter activity
- Increased cell proliferation
- Decreased cyclooxygenase activity