3β-Hydroxysteroid dehydrogenase
3β-Hydroxysteroid dehydrogenase/Δ⁵⁻⁴ isomerase is an enzyme that catalyzes the biosynthesis of the steroid progesterone from pregnenolone, 17α-hydroxyprogesterone from 17α-hydroxypregnenolone, and androstenedione from dehydroepiandrosterone in the... Wikipedia