ACE2 and COVID-19: The COVID-19 pathogenesis includes direct cytotoxicity of virus in ACE2 (angiotensin-converting enzyme 2)-expressing cells; Renin-Angiotensin-Aldosterone System (RAAS) dysregulation secondary to virus-mediated ACE2 downregulation; immune response dysregulation; damage to the endothelial cells and thromboinflammation; and tissue fibrosis (Figure 2) [9].