The protein encoded by this gene has both oxidoreductase and epimerase activities and is involved in androgen catabolism. The oxidoreductase activity can convert 3 alpha-adiol to dihydrotestosterone, while the epimerase activity can convert androsterone to epi-androsterone. Both reactions use NAD+ as the preferred cofactor. This gene is a member of the retinol dehydrogenase family. [provided by RefSeq, Aug 2013].