In the left atrium of patients with AF, nuclear NF-AT3 levels were correlated with PICP (p <0.01) and TGF-β1 levels (p <0.01), while nuclear NF-AT4 levels correlated with PICP (p <0.01) and TGF-β1 levels (p <0.05). This evidence concerns the gene TGFB1 and atrial fibrillation.