ACE2 and COVID-19: Also the observations that elevated plasma glucose levels and diabetes are independent risk factors for mortality and morbidity in patients with SARS (18) and COVID-19 (16, 19) are beyond doubt, but consideration needs to made that these could reflect, at least in part, a state of insulin resistance and elevated insulin levels that are driving increased ACE2 expression in lung epithelial cells and aggravating disease severity.