In type 1 and 2 diabetes mellitus, macrophages and associated cytokine IL-1β increase the risk of arrhythmogenesis by prolonging the action potential duration, inducing a decrease in potassium currents in cardiomyocytes and activating ryanodine receptor 2 channels, resulting in sarcoplasmic reticulum calcium ion leakage, which is found to be a trigger for AF [68,69]. The gene discussed is IL1B; the disease is atrial fibrillation.