ACE2 and COVID-19: Angiotensin-converting enzyme 2 (ACE2), a key enzyme of the renin-angiotensin-aldosterone system (RAAS) that maintains homeostasis of blood pressure, electrolytes, and the inflammatory response, is also a possible cause of COVID-19-related damage to the lung [12], heart [13], liver [14] and kidney [15] as SARS-CoV-2 enters cells through ACE2.