17β-estradiol completely reversed S protein-induced activation of NOX2 and reactive oxygen species production, angiotensin-converting enzyme 2 (ACE2) upregulation and induction of pro-inflammatory monocyte chemoattractant protein-1 (MCP-1) in endothelial cells, thus attenuating endothelial dysfunction [120]. Here, ACE2 is linked to endothelial dysfunction.