Families of transmembrane transporters selective for amino acids and their derivatives The information presented in this review was initially prepared for presentation at the FASEB meeting on amino acid transport held in Copper Mountain, Colorado, June 26–July 1, 1999 and was updated in January 2000 following the meeting of the Transport Nomenclature Panel of the International Union of Biochemistry and Molecular Biology (IUBMB) in Geneva, November 28–30, 1999. The system of classification described in this review reflects the recommendations of that panel.