At present, autoantibodies related to RA include ACPA, antikeratin antibodies (AKA), antiperinuclear factor (APF), antifibronectin antibody (AFA), antimutated citrullinated vimentin (anti-MCV) antibody, anti-Sa antibody, RF, antiglucose-6 phosphate isomerase (anti-GPI) antibody, anticarbamylated protein (anti-CarP) antibody, antiacetylated protein antibody, antinuclear antibody (ANA), antiheterogeneous nuclear ribonucleoprotein (anti-hnRNP/RA33) antibody, anti-Bip antibody and anticalcitostatin antibody (ACAST), and anti-CII antibody [12, 13]. Here, GPI is linked to rheumatoid arthritis.