DHRS4, also known as dehydrogenase/reductase SDR family member 4, belongs to the short-chain dehydrogenases/reductases (SDR) family. DHRS4 reduces all trans retinal and 9 cis retinal. This protein can also catalyze the oxidation of all trans retinol with NADP as cofactor, but with much lower efficiency. Also, DHRS4 reduces alkyl phenyl ketones and alpha dicarbonyl compounds with aromatic rings, such as pyrimidine 4 aldehyde, 3 benzoylpyridine, 4 benzoylpyridine, menadione and 4 hexanoylpyridine. Recombinant human DHRS4 protein, fused to His-tag at N-terminus, was expressed in E.coli and purified by using conventional chromatography. Synonyms: Dehydrogenase/reductase SDR family member 4, CR, NRDR, PHCR, PSCD, SCAD-SRL, SDR-SRL, SDR25C1, SDR25C2. NCBI no.: NP_066284