Anti-API5 antibodies are used in the immunodetection of the protein apoptosis inhibitor 5. In humans, the canonical protein has a reported length of 524 amino acid residues and a mass of 59 kDa. Its subcellular localization is in the nucleus and cytoplasm. Up to 6 different isoforms have been reported for this protein. It is reported to be expressed in all tissues tested, including heart, brain, placenta, lung, liver, skeletal muscle, kidney and pancreas. A member of the API5 protein family, API5 is reported to be an antiapoptotic factor that may have a role in protein assembly. Synonyms for this target antigen include AAC11, FIF, antiapoptosis clone 11 protein, cell migration-inducing gene 8 protein, fibroblast growth factor 2-interacting factor 2, and AAC-11. API5 gene orthologs have been reported in the mouse, rat, bovine, frog, zebrafish, chimpanzee and chicken species. Some API5 antibodies may have been used in research and have associated citations. Western Blot is a widely used application for these antibodies. ELISA and Immunohistochemistry are also common applications.