ACE2 and diabetes mellitus: Our previous study revealed that ACE2 gene is highly associated with diabetes4; loss of ACE2 leads to a decrease in insulin secretion, as well as a progressive impairment of glucose tolerance5,6; ACE2 pathway can ameliorate local blood flow, inflammation, stress state, and fibrosis, which leads to the improvement of glucose transport, lipolysis, and adipokines production.7–9 These findings may partly explain the higher morbidity and mortality in COVID-19 patients combined with diabetes.10