This gene encodes a member of the cytochrome P450 superfamily of enzymes. The cytochrome P450 proteins are;monooxygenases which catalyze many reactions involved in drug metabolism and synthesis of cholesterol, steroids and;other lipids. However, this protein is considered a member of the cytochrome P450 superfamily on the basis of sequence;similarity rather than functional similarity. This endoplasmic reticulum membrane protein catalyzes the conversion of;prostglandin H2 to prostacyclin (prostaglandin I2), a potent vasodilator and inhibitor of platelet aggregation. An;imbalance of prostacyclin and its physiological antagonist thromboxane A2 contribute to the development of myocardial;infarction, stroke, and atherosclerosis.