Notably, the citrullinated forms of fibrinogen, fibronectin (Fn), fibrin, vimentin, collagen type II and α-enolase are common in the inflamed synovium and citrullinated fibrinogen, citrullinated fibronectin (cFn), citrullinated fibrin and citrullinated vimentin in the inflamed synovium and plasma have been considered as important citrullinated autoantigens in RA [4,7-12]. The gene discussed is FN1; the disease is rheumatoid arthritis.