all-trans 5,6-Epoxy Retinoic Acid-d5 is the labeled analog of all-trans 5,6-Epoxy Retinoic Acid (E589800), a metabolite of all-trans Retinoic acid (R250200), a physiological metabolite of vitamin A. Effects gene expression via nuclear retinoic acid receptors (RAR); mediates cellular growth and differentiation.