A prospective cohort design based on the Copenhagen City Heart Study reported that serum ALB levels only in females were inversely related to the risk of AF (hazard ratio: 0.47, 95% CI 0.28–0.77), which was inconsistent with our current results reporting that low serum low ALB levels in male patients were associated with paroxysmal AF. The gene discussed is ALB; the disease is Paroxysmal atrial fibrillation.