ACE2 and diabetes mellitus: Thus, it would be relevant to explore the expression of ACE2 in hypertensive patients relative to non-hypertensive patients, but, in our literature review, scientific evidence concerning hypertension and COVID-19 focused almost exclusively on the possible effects of RAAS inhibitors (commonly prescribed drugs for various indications, such as hypertension, myocardial infarction, cardiac failure, kidney diseases, and complications of diabetes all over the globe) and not on the purpose of our review.