Although there are no reports about the direct relationship between FCGR3B and atrial fibrillation, the mechanism of atrial fibrosis in atrial fibrillation mentioned above is consistent with the mechanism of pulmonary fibrosis caused by FCGR3B, so FCGR3B may be a potential biomarker for the maintenance of atrial fibrillation. The gene discussed is FCGR3B; the disease is pulmonary fibrosis.