Anti-APA antibodies are used in antigen-specific immunodetection in biological samples. The target APA is a known alias name of the protein glutamyl aminopeptidase, encoded by the ENPEP gene in humans. This 957-amino acid residue protein is reported to regulate central hypertension through its calcium-modulated preference to cleave N-terminal acidic residues from peptides such as angiotensin II. It is localized to the cell membrane of the cell and features glycosylated post-translational modifications. In terms of tissue expression, it is reported to be expressed in choriocarcinoma cancer cell lines. Other synonyms for APA include CD249 and gp160.