MiR-338-5p targeted 14 of our DEGs, including IGFBP2, LBH and NPPA. IGFBP2 and LBH have both been reported as up-regulated in three different AF studies and they are increased by 8 and 3 FC in our RA samples, respectively [36–38,40]. The gene discussed is IGFBP2; the disease is atrial fibrillation.