Anti-CSTA antibodies are used in the immunodetection of the protein cystatin A. In humans, the canonical protein has a reported length of 98 amino acid residues and a mass of 11 kDa. Its subcellular localization is in the cytoplasm. It is reported to be expressed in the skin throughout the epidermis. A member of the Cystatin protein family, CSTA is an intracellular thiol proteinase inhibitor. The CSTA marker can be used to identify Type 2 Medullary Thymic Epithelial Cells.* Synonyms for this target antigen include PSS4, STF1, STFA, cystatin A (stefin A), cystatin AS, and AREI. CSTA gene orthologs have been reported in the mouse, rat, bovine and chimpanzee species.
*HuBMAP Human Reference Atlas v1.4