“…This gene is associated with a number of other traits, including risk factors for COVID-19 morbidity and mortality. For example, genome-wide association studies have associated variants within ABO to activity of the angiotensin converting enzyme 7 , red blood cell count, hemoglobin concentration, hematocrit [8][9][10][11] , von Willebrand factor [12][13][14][15] , myocardial infarction 16,17 , coronary artery disease [17][18][19][20][21] , ischemic stroke 13,19,22 , type 2 diabetes [23][24][25] , and venous thromboembolism [26][27][28][29][30][31][32][33] . A 2012 meta-analysis found that, in addition to individual variants, a non-O blood type is among the most important genetic risk factors for venous thromboembolism 34 .…”