Anti-FOXO1 antibodies are used in the immunodetection of the protein forkhead box O1. In humans, the canonical protein has a reported length of 655 amino acid residues and a mass of 69.7 kDa. Its subcellular localization is in the nucleus and cytoplasm. It is ubiquitously expressed across many tissue types. FOXO1 is reported to be a transcription factor that is the main target of insulin signaling and regulates metabolic homeostasis in response to oxidative stress. Post-translational modifications have been described, including ubiquitination, acetylation and phosphorylation. The FOXO1 gene has been associated with the disease, Rhabdomyosarcoma. Synonyms for this target antigen include FKHR, FOXO1A, forkhead box protein O1, forkhead box protein O1A, forkhead, Drosophila, homolog of, in rhabdomyosarcoma, and FKH1. FOXO1 gene orthologs have been reported in the mouse, rat, bovine, frog, chimpanzee and chicken species.