ACE2 is expressed primarily in the nasal goblet cells and type II pneumocytes within the respiratory tract,33 and it is upregulated in subject groups known to be associated with increased disease severity, including elderly individuals34 and patients with diabetes,17 indicating that it may play a clinically important role in governing susceptibility to virus acquisition and/or development of severe disease in at-risk groups. This evidence concerns the gene ACE2 and diabetes mellitus.