Catalyzes the NADPH-dependent reduction of a variety of substrates including aromatic and aliphatic aldehydes, quinones, ketones, dicarbonyl compounds and 17-ketosteroids (PubMed:17574202). Catalyzes the NADP(+)-dependent oxidation of aromatic, alicyclic and aliphatic alcohols, and 17beta-hydroxysteroids (PubMed:17574202). To a lesser extent, can also catalyze the reduction of some aldoses and ketoses and the oxidation of some sugar alcohols (PubMed:17574202). In the stomach, lung and colon tissues, mediates the reduction of farnesal and geranylgeranial into farnesol and geranylgeraniol respectively (PubMed:21187079). By reducing 4-hydroxy-2-nonenal (HNE), produced during lipid peroxidation, into 1,4-dihydro-2-nonene (DHN), protects vascular endothelial cells from damage elicited by oxidized lipoproteins (PubMed:21187080). (2E,6E)-farnesol + NADP(+) = (2E,6E)-farnesal + H(+) + NADPH The dehydrogenase activity is inhibited by 3',3'',5',5''-tetraiodophenolphthalein, phenolphthalein, genistein, quercetin, zearalenone and diethylstilbestrol. Optimum pH is 10.5 for the dehydrogenase activity. Optimum pH is 6 for the reductase activity. Monomer. Expressed in lung, specifically in bronchiolar Clara cells, type II alveolar cells and epithelial cells of the duct of the bronchial gland (at protein level) (PubMed:17574202, PubMed:7511002, PubMed:21187079). Expressed in gastric parietal cells and in epithelial cells of the large intestine and colon (at protein level) (PubMed:17574202, PubMed:21187079). Expressed in brown adipocytes (at protein level) (PubMed:17574202). Expressed in vascular endothelial cells (at protein level) (PubMed:17574202). Belongs to the aldo/keto reductase family.