Anti-Cystatin B antibodies are used in the immunodetection of the protein encoded by the CSTB gene. In humans, the canonical protein has a reported length of 98 amino acid residues and a mass of 11.1 kDa. Its subcellular localization is in the nucleus and cytoplasm. A member of the Cystatin protein family, it is an intracellular thiol proteinase inhibitor. Other names for this target antigen include CST6, EPM1, EPM1A, PME, STFB, ULD, cystatin B (stefin B), and CPI-B.