Human filaggrin, α-enolase, fibrinogen, fibronectin, vimentin, collagen II, immunoglobulin-binding protein (BiP), and histone proteins are some of the citrullinated targets for autoantibodies from RA patients [12,52,76,77,78,79,80,81,82,83]. This evidence concerns the gene HSPA5 and rheumatoid arthritis.