Aldehyde dehydrogenase 1 family, member A3 (ALDH1A3), also known as Retinaldehyde dehydrogenase 3 (RALDH3), which belongs to the aldehyde dehydrogenase family. ALDH1A3 is a novel Cancer stem cell (CSC) marker with potential clinical prognostic applicability, and demonstrates a clear correlation between CSC prevalence and the development of metastatic breast cancer. The retinoic acid (RA) biosynthesis enzyme aldehyde dehydrogenase 1A3 (ALDH1A3) is a putative androgen-responsive gene in human prostate cancer epithelial (LNCaP) cells. The RA biosynthesis enzyme ALDH1A3 is androgen responsive and (ii) DHT up-regulation of ALDH1A3 can increase the oxidation of retinal to RA and indirectly affect RA bioactivity and metabolism.