However, anti‐RgpB levels were slightly lower in RA patients compared to OA patients (mean ± SD 0.44 ± 0.50 μg/ml versus 0.36 ± 0.45 μg/ml; P = 0.0353), and there was no difference in anti‐RgpB levels between CCP‐2–positive patients and CCP‐2–negative patients (mean ± SD 0.34 ± 0.46 μg/ml versus 0.35 ± 0.44 μg/ml; P = 0.4988) (Supplementary Figures 3B and C). The gene discussed is AGBL2; the disease is rheumatoid arthritis.