Highly expressed in type II alveolar epithelial cells (as well as arterial/ venous endothelium and arterial smooth muscle cells), the angiotensin converting enzyme-2 (ACE-2) receptor has been identified as the gateway to infection for the SARS and SARS-CoV-2 coronaviruses, with SARS-CoV-2 having a 10-fold increased affinity than its predecessor [65,66,67]. This evidence concerns the gene ACE2 and infection.