ACE2 and obesity due to melanocortin 4 receptor deficiency: Elevated Ang II is a prominent feature of various comorbidities – such as diabetes, obesity, and hypertension – and may account for the elevated risk of severe COVID-19 in these patients (31, 32) SARS-CoV-2 utilizes ACE2 for viral entry into cells and the continuous recycling of ACE2 upon SARS-CoV-2 cell entry – i.e., repetitive endocytosis and recirculation back to the cell surface – eventually results in a net downregulation of ACE2 and a chronic ACE2 deficiency (33).