Figure 4

The association between SARS-CoV-2 and the Renin-Angiotensin-Aldosterone System (RAAS). SARS-CoV-2 binds to ACE2 receptor and enters into the cell. It has been hypothesized that this process leads to down-regulation of surface ACE2, resulting in unopposed angiotensin II buildup and activity, leading to a pro-inflammatory cascade. Alternative hypotheses are further described in the text. The uncertainties regarding the role of ACE-Is and ARBs in COVID-19 are also discussed. Ang, angiotensin; ACE, angiotensin-converting enzyme; AT1, angiotensin II type 1 receptor.