Although anti-MCV could detect patients with poor radiological prognosis also among anti-CCP2-negative patients (33), and high levels of anti-MCV have been particularly associated with severe extra-articular manifestations of RA (34), a number of studies have raised issues concerning the diagnostic performance of anti-MCV, especially in the high specificity part of the receiver operator characteristics (ROC) curve (35, 36). Here, AGBL2 is linked to rheumatoid arthritis.