ANGPT1 and COVID-19: Reduced expression of ACE2 has been shown to cause an increase in vascular permeability via the activation of KKS [81,87], and thus an increased ACE2/Ang 1–7 activity in pregnancy may support vascular integrity, sustain impermeability and promote balanced coagulative endothelium via the MAS receptor and the KKS, thereby protecting COVID-19 pregnant women against ARDS.