The major findings of the present study were: (1) Patients with AF show marked differences with increased levels of ET-1 and MCP-1 and reduced levels of CGA compared to healthy controls; (2) in AF patients higher ET-1 levels were associated with AF recurrence three months after PVI; (3) freedom from AF after ablation was associated with a significant decrease of ET-1 and a significant increase of CGA three months after ablation compared to baseline. The gene discussed is CCL2; the disease is atrial fibrillation.