Anti-FOXO3 antibodies are used in the immunodetection of the protein forkhead box O3. In humans, the canonical protein has a reported length of 673 amino acid residues and a mass of 71.3 kDa. Its subcellular localization is in the membrane, nucleus, mitochondria, and cytoplasm. Up to 2 different isoforms have been reported for this protein. It is ubiquitously expressed across many tissue types. FOXO3 is reported to be a transcriptional activator that recognizes and binds to the DNA sequence 5'-[AG]TAAA[TC]A-3' and regulates different processes, such as apoptosis and autophagy. Synonyms for this target antigen include FKHRL1, FKHRL1P2, FOXO2, FOXO3A, forkhead box protein O3, FOXO3A-, forkhead box O3A, and AF6q21. FOXO3 gene orthologs have been reported in the mouse, rat, bovine, frog, chimpanzee and chicken species. Over 1500 citations in the literature describe the use of FOXO3 antibodies in research. Western Blot is a widely used application for these antibodies. ELISA, Immunofluorescence, and Immunohistochemistry are also common applications.