Anti-CAST antibodies are used in the immunodetection of the protein calpastatin. In humans, the canonical protein has a reported length of 708 amino acid residues and a mass of 76.6 kDa. Up to 1 different isoforms have been reported for this protein. It is notably widely expressed in many tissue types. It is a member of the Protease inhibitor I27 (calpastatin) protein family. The CAST gene has been associated with the disease, Peeling skin with leukonychia, acral punctate keratoses, cheilitis, and knuckle pads. Synonyms for this target antigen include PLACK, calpain inhibitor, sperm BS-17 component, and BS-17. CAST gene orthologs have been reported in the mouse, rat, bovine, frog, zebrafish, chimpanzee and chicken species. Over 60 citations in the literature describe the use of CAST antibodies in research. Western Blot, Immunofluorescence, and Immunohistochemistry are common applications for these antibodies.