REN and endothelial dysfunction: Although reduced surface expression of endothelial hACE2 by SARS-CoV2 RBD would be expected to decrease infectivity of the virus in capillaries and as such protect this compartment, a dysregulated renin-angiotensin system due to a disturbed ACE2/ACE balance will rather aggravate endothelial dysfunction in COVID-19 (33).