Interestingly, Matson et al. recently reported that ACPA was detected in bronchoalveolar lavage fluid in approximately 20% of patients with IPF, and the prognosis of patients with IPF who tested positive for IgA-ACPA was significantly better than that of patients with IPF who tested negative for ACPA. This evidence concerns the gene PRTN3 and idiopathic pulmonary fibrosis.