Anti-CFAP91 antibodies are used in the immunodetection of the protein cilia and flagella associated protein 91. In humans, the canonical protein has a reported length of 767 amino acid residues and a mass of 90 kDa. Its subcellular localization is in the mitochondria and cytoplasm. Up to 7 different isoforms have been reported for this protein. It is notably expressed in the bronchus and fallopian tube. A member of the CFAP91 protein family, CFAP91 is known to be involved in sperm flagellum axonemal organization and function. Post-translational modifications have been described, including phosphorylation. The CFAP91 gene has been associated with the disease, Spermatogenic failure. Synonyms for this target antigen include AAT1-alpha, AMY-1-associating protein expressed in testis 1, MYCBP associated and testis expressed 1, MYCBP-associated, testis expressed 1, MYCBP-binding protein, and AAT-1. CFAP91 gene orthologs have been reported in the mouse, rat, bovine, frog, zebrafish, chimpanzee and chicken species.