Anti-Complement factor I antibodies are used for the immunodetection of the protein encoded by the CFI gene. In humans, the canonical protein has a reported length of 583 amino acid residues and a mass of 65.8 kDa. It is known to be a secreted protein. It is reported to be expressed in the liver by hepatocytes. A member of the Peptidase S1 protein family, it is known to be involved with innate immune responses and proteolysis. Post-translational modifications have been described, including glycosylation. The gene encoding this protein is implicated in Hemolytic uremic syndrome atypical. Other names for this target antigen include ARMD13, C3BINA, C3b-INA, FI, IF, KAF, C3B/C4B inactivator, and AHUS3. Gene orthologs have been identified in the mouse, rat, bovine, frog, zebrafish, chimpanzee and chicken species. A number of Complement factor I antibodies have been mentioned in research publications and have associated citations. Western Blot is a widely used application for these antibodies. In addition, Immunohistochemistry is also a common application.