title: Retinoic acid: an endogenous compound of human blood. Unequivocal demonstration of endogenous retinoic acid in normal physiological conditions.
mesh_terms: D002849:Chromatography, Gas / Q000379:methods; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D006801:Humans; D013058:Mass Spectrometry / Q000379:methods; D014212:Tretinoin / Q000097:blood*
chemical_list: D014212:Tretinoin