However, the fact that both SARS-CoV and SARS-CoV-2 recognize ACE2 as a receptor has given rise to the hypothesis that in addition to the aforementioned mechanisms (which may be further exacerbated by the secondary bacterial infection), the pathology of COVID-19 or SARS may be to a large extent associated with the virus-induced imbalance of the renin-angiotensin system (RAS) [9, 10]. Here, ACE2 is linked to bacterial infectious disease.