Claim: Although HSD3B2 is principally expressed in steroidogenic tissues, and essential for steroid hormone production, one notable exception is the placenta, where HSD3B1 (another human gene) is critical for progesterone production by the placenta tissue.
Evidence: It is expressed principally in steroidogenic tissues and is essential for steroid hormone production. A notable exception is the placenta, where HSD3B1 is critical for progesterone production by this tissue. HSD3B1 is a human gene that encodes for a 3beta-hydroxysteroid dehydrogenase/delta(5)-delta(4)isomerase type I or hydroxy-delta-5-steroid dehydrogenase, 3 beta- and steroid delta-isomerase 1.