Plasma IL-1β levels in corresponding 24 non-AF controls and 21 AF patients from this study cohort were measured by an ELISA assay, finding that significantly higher IL-1β levels in AF patients than in controls (AF patients vs. Controls, 8.53 ± 4.10 vs. 3.95 ± 2.42 pg/mL; P < 0.001) (Fig. 1E). This evidence concerns the gene IL1B and atrial fibrillation.