GPX1 and atrial fibrillation: Finally, the real-time PCR analysis revealed a downregulated expression of SOD1, SOD2, and GPx1 genes in patients with AF-PBC presenting SOS imbalance compared with patients with AF-PBC with a balanced systemic oxidative status (SOD1, p = 0.02; SOD2, p = 0.03; GPx1, p = 0.02) (Figure 8).