This article summarizes the role of OS biomarkers such as 8-hydroxydeoxyguanosine (8-OHdG), glutathione peroxidase (GPx), advanced glycation end-products (AGEs), superoxide dismutase (SOD), malondialdehyde (MDA), isoprostanes (IsoPs), derivatives of reactive oxidative metabolites that oxidize reduced glutathione (E<sub>h</sub> GSH) and cysteine, and advanced oxidation protein products (AOPPs) in the pathogenesis of AF. The gene discussed is SOD1; the disease is atrial fibrillation.