Rat Cytochrome P450 19A1, CYP19A1 ELI

Aromatase, also called estrogen synthetase or estrogen synthase, is an enzyme responsible for a key step in the biosynthesis of estrogens.

It is CYP19A1, a member of the cytochrome P450 superfamily (EC 1.14.14.1), which are monooxygenases that catalyze many reactions involved in steroidogenesis.

In particular, aromatase is responsible for the aromatization of androgens into estrogens.

The enzyme aromatase can be found in many tissues including gonads (granulosa cells), brain, adipose tissue, placenta, blood vessels, skin, and bone, as well as in tissue of endometriosis, uterine fibroids, breast cancer, and endometrial cancer.[citation needed] It is an important factor in sexual development.