AKR1C2 is a member of the aldo/keto reductase superfamily, which consists of more than 4 known enzymes and proteins. These enzymes catalyze the conversion of aldehydes and ketones to their corresponding alcohols using NADH and/or NADPH as cofactors. The enzymes display overlapping but distinct substrate specificity. This enzyme binds bile acid with high affinity, and shows minimal 3-alpha-hydroxysteroid dehydrogenase activity. AKR1C2 gene shares high sequence identity with three other gene members and is clustered with those three genes at chromosome 1p15-p14. Three transcript variants encoding two different isoforms have been found for AKR1C2 gene.