In this regard, a history of comorbidities have been reported as risk factors for severity of COVID-19, including hypertension due to the imbalance between the two major pathways of the renin–angiotensin–aldosterone system (RAAS), with ACE2/Ang 1-7 downregulation and ACE2/Ang II upregulation. This evidence concerns the gene ACE2 and COVID-19.