In patients with atherosclerosis, hypertension, endotoxic shock or infectious diseases, an increase in endothelin-1 has been described, which is attributed pro-inflammatory activities, platelet aggregation and also plays a role in the increase in the expression of adhesion molecules of leukocytes (68), causing endothelial cell injury; this endothelial dysfunction is also consistent and is related to mortality in patients with COVID-19 (69), in severe patients with MIS-C endothelial dysfunction could explain its clinical presentation (Figure 2). The gene discussed is EDN1; the disease is endothelial dysfunction.