The Lysosomal Cystine Transporter (LCT) family (TC# 2.A.43] is part of the TOG Superfamily and includes secondary transport proteins that are derived from animals, plants, fungi and other eukaryotes. They exhibit 7 putative transmembrane a-helical spanners (TMSs) and vary in size between about 200 and 500 amino acyl residues, although most have between 300 and 400 residues.