For example, several citrullinated autoantigens can be identified in tests for anti-citrullinated peptide antibodies (ACPA; Anti-cyclic Citrullinated Peptide; Anti-CCP), keratin, fibrinogen, fibronectin (FN), collagen, and vimentin from patients with arthritis (111, 112). The gene discussed is FN1; the disease is Arthritis.