IL1B and atrial fibrillation: Regarding the expression of inflammatory markers, as expected, IL-1β stimulation induced the upregulation of IL-6 and IL-8 gene expression and PGE2 secretion by AF cells (*p < 0.05, **p < 0.01 and ***p < 0.001, respectively) in comparison to unstimulated cells (Figures 2F–H).