Anti-CYP21A2 antibodies are used in the immunodetection of the protein cytochrome P450 family 21 subfamily A member 2. In humans, the canonical protein has a reported length of 494 amino acid residues and a mass of 55.9 kDa. Its subcellular localization is in the ER. Up to 2 different isoforms have been reported for this protein. It is notably expressed in the adrenal gland. A member of the Cytochrome P450 protein family, CYP21A2 is a cytochrome P450 monooxygenase that plays a major role in adrenal steroidogenesis. The CYP21A2 gene has been associated with the disease, Adrenal hyperplasia. Synonyms for this target antigen include CAH1, CPS1, CYP21, CYP21B, P450c21B, steroid 21-hydroxylase, 21-OHase, and CA21H. CYP21A2 gene orthologs have been reported in the mouse, rat, bovine, frog and chicken species. A number of CYP21A2 antibodies have been mentioned in research publications and have associated citations. Western Blot is a widely used application for these antibodies. ELISA, Immunofluorescence, and Immunohistochemistry are also common applications.