DHRS7 (dehydrogenase/reductase (SDR family) member 7), also known as SDR34C1, CGI-86 or retSDR4, is a 339 amino acid member of the SDR family. Like other members of the SDR family, DHRS7 contains a cofactor-binding Rossman-fold domain and is thought to catalyze the oxidation and reduction of a variety of substrates such as steroids and retinoids. DHRS7 exists as two alternatively spliced isoforms that are encoded by a gene located on human chromosome 14, which houses over 700 genes and comprises nearly 3.5% of the human genome. Chromosome 14 encodes the presinilin 1 (PSEN1) gene, which is one of the three key genes associated with the development of Alzheimer's disease (AD). The SERPINA1 gene is also located on chromosome 14 and, when defective, leads to the genetic disorder ?-antitrypsin deficiency, which is characterized by severe lung complications and liver dysfunction.