 It is also present in other steroid-producing tissues, including the ovary, testis and placenta.In humans, there are two 3β-HSD isozymes encoded by the HSD3B1 and HSD3B2 genes.3β-HSD is also known as delta Δ5-4-isomerase, which catalyzes the oxidative conversion of Δ5-3β-hydroxysteroids to the Δ4-3-keto configuration and is, therefore, essential for the biosynthesis of all classes of hormonal steroids, namely progesterone, glucocorticoids, mineralocorticoids, androgens, and estrogens.