Angiotensin converting enzyme-2 (ACE2) receptors mediate the entry into the cell of three strains of coronavirus: SARS-CoV, NL63 and SARS-CoV-2. ACE2 receptors are ubiquitous and widely expressed in the heart, vessels, gut, lung (particularly in type2 pneumocytes and macrophages), kidney, testisand brain. ACE2 is mostly bound to cell membranes and only scarcely present in the circulation in a s...