In addition to the bradykinin system, ACE2 interacts also with the renin-angiotensin system and the coagulation system; thus, it has been proposed that SARS-CoV-2/ACE2 interaction could be in the center of the multisystemic abnormalities that are common to patients with severe COVID-19, such as inflammation, coagulopathy, and cardiovascular failure [16]. Here, REN is linked to blood coagulation disease.