On the other hand, in a clinical study that evaluated 218 patients with AF who underwent catheter ablation and 268 controls, a polymorphism in the EPHX2 gene, which encodes human sEH, was associated with a higher risk of AF recurrence after catheter ablation within 12 months (OR 3.2, 95% CI 1.237–8.276, p = 0.016) and 24 months (OR 6.076, 95% CI 2.244–16.451, p < 0.0001). This evidence concerns the gene EPHX2 and atrial fibrillation.