KCNJ2 and atrial fibrillation: Previous researches have shown that Kir2.1 expression and IK1 density were increased in patients with AF,24 and miR‐26 functions as an AF suppressor by targeting KCNJ2. 25, 26Compared to the non‐AF group, the expression of KCNJ2 was elevated at both the mRNA and protein levels in the atria of AF models in our study (Figure 4A,B).