Additionally, another recent study revealed that the SARS-CoV-2 spike protein alone can damage endothelium, with the damage manifested by impaired mitochondrial function and endothelial NOS activity, but that increased glycolysis, a dysregulated renin-angiotensin system, due to ACE2 reduction may exacerbate endothelial dysfunction, leading to endotheliitis [55]. This evidence concerns the gene ACE2 and endothelial dysfunction.