ACE2 and COVID-19: Combining the information currently available regarding the pathophysiology of SARS-CoV-2 infection, the negative implications in the body of sustained hyperglycemia related or not to DM, as well as the beneficial effect of glycemic control in COVID-19 patients, indicate the importance of ACE2 in lung protection and its participation in the correct functioning of other tissues, and the deleterious effects of the absence of ACE2.