Citrullinated fibrinogen (β chain) (R44 + R47 + R60) (41-62)-biotin peptide is a biotinylated version of a tri-citrullinated form of the secreted matrix protein fibrinogen, which has been found as the citrullinated form in plasma circulating immune complexes of patients with rheumatoid arthritis.1 Fibrinogen is subject to citrullination by peptidyl arginine deiminase 2 (PAD2) and PAD4, which can occur in the synovial fluid from patients with rheumatoid arthritis.2,3 Cayman's Citrullinated Fibrinogen (β Chain) (R44 + R47 + R60) (41-62)-biotin Peptide is intended for the detection of autoantibodies against fibrinogen citrullinated at R44, R47, and R60.WARNING This product is not for human or veterinary use.