For example, genome-wide association studies have associated variants within ABO to activity of the angiotensin converting enzyme (ACE) [6], red blood cell count, hemoglobin concentration, hematocrit, [7,8,9,10], von Willebrand factor [11,12,13,14], myocardial infarction [15,16],coronary artery disease [16,17,18,19,20], ischemic stroke [12,18,21], type 2 diabetes [22,23,24], and venous thromboembolism [25,26,27,28,29,30,31,32]. The gene discussed is ACE; the disease is ischemic stroke.