Anti-CTNS antibodies are used in the immunodetection of the protein cystinosin, lysosomal cystine transporter. In humans, the canonical protein has a reported length of 367 amino acid residues and a mass of 41.7 kDa. Its subcellular localization is in the lysosomes and cell membrane. Alternative splicing is reported to yield 2 different isoforms for this protein. It is reported to be highly expressed in pancreas, kidney (adult and fetal), skeletal muscle, melanocytes and keratinocytes. A member of a the Cystinosin protein family, CTNS is reported to be a Cystine/H(+) symporter that mediates export of cystine, the oxidized dimer of cysteine, from lysosomes. Post-translational modifications have been described, including glycosylation. Synonyms for this target antigen include PQLC4, SLC66A4, cystinosin, cystinosis nephropathic, and CTNS-LSB.