AF cases had significantly higher levels of circulating platelet factor-4, β-thromboglobulin (BTG), and P-selectin when compared to controls in terms of platelet activation, respectively, as to coagulation activation; increased levels of plasma D-dimer, fibrinogen, thrombin-antithrombin, prothrombin fragment 1 + 2, and antithrombin-III were significantly associated with AF. The gene discussed is SELP; the disease is atrial fibrillation.