The function of AKR1B15 (aldo-keto reductase family 1 member B15, ENSG00000227471) is as follows. [Isoform 1]: Catalyzes the NADPH-dependent reduction of a variety of carbonyl substrates, like aromatic aldehydes, alkenals, ketones and alpha-dicarbonyl compounds (PubMed:21276782, PubMed:26222439). In addition, catalyzes the reduction of androgens and estrogens with high positional selectivity (shows 17-beta- hydroxysteroid dehydrogenase activity) as well as 3-keto-acyl-CoAs (PubMed:25577493). Displays strong enzymatic activity toward all-trans- retinal and 9-cis-retinal (PubMed:26222439). May play a physiological role in retinoid metabolism (PubMed:26222439). {ECO:0000269|PubMed:21276782, ECO:0000269|PubMed:25577493, ECO:0000269|PubMed:26222439}. [Isoform 2]: No oxidoreductase activity observed with the tested substrates. .