(3) Results: Patients aged below 75 years with AF had significantly higher values of IL-6 and IL-6/IL-10 ratio; IL-6 levels were a significant predictor of AF in both univariate (OR 1.175; 95%CI 1.013–1.363; p = 0.034) and multivariate logistic regression analysis when accounting for other inflammatory biomarkers (OR 1.327; 95% CI 1.068–1.650; p = 0.011). This evidence concerns the gene IL10 and atrial fibrillation.