Anti-CTSB antibodies are used in the immunodetection of the protein cathepsin B. In humans, the canonical protein has a reported length of 339 amino acid residues and a mass of 37.8 kDa. Its subcellular localization is in the lysosomes and cell membrane. It is reported to be expressed in the stratum spinosum of the epidermis. A member of the Peptidase C1 protein family, CTSB is reported to be a thiol protease, which is believed to participate in intracellular degradation and turnover of proteins. The CTSB gene has been associated with the disease, Keratolytic winter erythema. Synonyms for this target antigen include CPSB, KWE, RECEUP, APP secretase, amyloid precursor protein secretase, cathepsin B1, cysteine protease, and APPS. CTSB gene orthologs have been reported in the mouse, rat, bovine, frog, zebrafish, chimpanzee and chicken species. Over 320 citations in the literature describe the use of CTSB antibodies in research. ELISA, Western Blot, and Immunohistochemistry are common applications for these antibodies.