Compared with Pg antibody-negative patients, early RA patients with positive Pg responses more often had anti-cyclic citrullinated peptide (anti-CCP) antibody reactivity, their anti-CCP levels were significantly higher (P = 0.03) and the levels of anti-Pg antibodies correlated directly with anti-CCP levels (P < 0.01). The gene discussed is JUP; the disease is rheumatoid arthritis.