An association between anti-CCP2 levels and the number of citrullinated peptides recognized has been described in RA using an ELISA test [27] or microarray techniques [27–29], and was observed in RA patients in the present study; however, we found that this association was observed to a lesser extent in PR, although the low number of recognized epitopes in PR patients limits data interpretation. Here, AGBL2 is linked to rheumatoid arthritis.