ACE2 and diabetes mellitus: There are several potential reasons for myocardial cell injury in COVID-19 patients, including systemic inflammatory responses, ACE2-targeted SAS-Cov-2 attacks on myocardial and lung cells, adverse effects of some anti-virus drugs (Clerkin et al., 2020), and some underlying myocardial-damaging co-morbidities, such as diabetes and hypertension.