One of the main histological findings in COVID-19 ARDS is a significant endothelial involvement due to viral antigen exposure and cytokine activation that leads to inflammation activation and possible cytokine storm, mostly through the activation of an angiotensin-converting enzyme 2 (ACE2) receptor (expressed in pulmonary endothelial cells, alveolar epithelial type II cells, heart, intestine, and kidney). The gene discussed is ACE2; the disease is COVID-19.