ACE2 is a polymorphic gene with genetic variants that have been associated with several diseases including hypertension, atrial fibrillation, diabetes mellitus, dilated cardiomyopathy, HDL, hypertrophic cardiomyopathy, high sensitivity C-reactive protein, intima media thickness, left ventricular hypertrophy, pulse pressure and small for gestational age birth (Fig. 1, Additional file 1) [14]. The gene discussed is ACE2; the disease is atrial fibrillation.