The association of CitH3 (114–135) antibody with pulmonary fibrosis was weakened when stratifying patients for RF positivity (OR = 2.25 (95%CI 0.82, 6.19) and anti-CCP2 antibody positivity (OR = 2.38 (95%CI 0.89, 6.40). This evidence concerns the gene AGBL2 and pulmonary fibrosis.