NADPH-dependent oxidoreductase which catalyzes the reduction of a variety of compounds bearing carbonyl groups including steroids, retinoids and xenobiotics (PubMed:24246760, PubMed:26466768, PubMed:28687384, PubMed:28457967). Catalyzes the reduction/inactivation of 5alpha-dihydrotestosterone to 3alpha-androstanediol, with a possible role in the modulation of androgen receptor function (PubMed:28687384, PubMed:28457967). Involved in the reduction of all-trans-retinal to all-trans-retinol (PubMed:26466768). Converts cortisone to 20beta-dihydrocortisone in vitro, although the physiological relevance of this activity is questionable (PubMed:28457967). Reduces exogenous compounds such as quinones (1,2-naphtoquinone, 9,10-phenantrenequinone and benzoquinone) and other xenobiotics (alpha-diketones) in vitro, suggesting a role in the biotransformation of xenobiotics with carbonyl group (PubMed:24246760, PubMed:26466768). A dehydrogenase activity has not been detected so far (PubMed:24246760). May play a role as tumor suppressor (PubMed:26311046). all-trans-retinol + NADP(+) = all-trans-retinal + H(+) + NADPH 5alpha-androstane-3alpha,17beta-diol + NADP(+) = 17beta-hydroxy-5alpha-androstan-3-one + H(+) + NADPH kcat is 10.22 min(-1) for the NADPH-dependent reduction of all-trans-retinal. Bound to the endoplasmic reticulum membrane, possibly through a N-terminus anchor. The main bulk of the polypeptide chain was first reported to be facing toward the lumen of the endoplasmic reticulum (PubMed:24246760). However, it was later shown to be facing the cytosol (PubMed:28457967). Found predominantly in the adrenal glands, liver, thyroid, prostate, small intestine, colon, stomach, kidney and brain (PubMed:26466768). Lower levels observed in skeletal muscle, the lung and the spleen (PubMed:26466768). Belongs to the short-chain dehydrogenases/reductases (SDR) family. DHRS7 was originally reported to be anchored in the endoplasmic reticulum membrane and facing the lumen (PubMed:24246760). However, the catalytic moiety was later shown to be facing the cytosol (PubMed:28457967).