With the recommended cutoff values of 20.0 U/ml for the anti-MCV test and 10.0 U/ml for the CCP2 ELISA, both assays showed a sensitivity of 65.3% (50.4%–78.3%) to detect patients with RA; however, the specificity of the anti-MCV test (91.5%; 87.0%–94.8%) was lower than that of the anti-CCP2 ELISA (98.7%; 96.1%–99.7%). The gene discussed is AGBL2; the disease is rheumatoid arthritis.