IL2 and atrial fibrillation: In this study, the level of peripheral blood serum IL-2 was found to be increased by 42.38% in patients with AF compared to that in normal controls (**p < 0.01, Figure 1A); miR-190a-5p was downregulated, while IL-2 was upregulated in human AF cardiac tissues compared to that in non-AF controls (Figure 3).