KCNJ2 and atrial fibrillation: Girmatsion et al. reported that miR-1 levels decreased significantly in human AF and led to increased IK1 possibly by up-regulating of KCNJ2 (39), miR-26 was found to be downregulated accompanied by upregulation of IK1/Kir2.1 protein in atrial samples of AF patients (40).