The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), responsible for COVID-19, achieves cell entry through an S (spike) high-affinity protein binding to the catalytic domain of the angiotensin-converting enzyme 2 (ACE2), a negative regulator of the renin–angiotensin system (RAS) pathway that has been shown to have protective effects in animal models of hypertension. Here, ACE2 is linked to COVID-19.