Aldo-keto reductase that functions as a bi-directional 17 BETA, 20 ALPHA-HYDROXYSTEROID DEHYDROGENASE. It catalyzes the reduction of PROSTAGLANDIN D2 and PROSTAGLANDIN H2, as well as the oxidation of 9alpha,11beta-PGF2 to prostaglandin D2. It can also interconvert estrogens, ANDROGENS; and PROGESTINS between their active forms and inactive metabolites.

Synonyms: AKR1C3 Protein, Aldo-Keto Reductase Family 1 Member C3, 17-beta-Hydroxysteroid Dehydrogenase Type 5, Aldo Keto Reductase Family 1 Member C3, Dihydrodiol Dehydrogenase 3, EC 1.1.1.357, 17 beta Hydroxysteroid Dehydrogenase Type 5