Young, healthy, and physically fit individual will tend to express more of angiotensin 1-7 which allows for regulation of the pathway and cleavage of ACE2 by enzyme sheddase, leading to less expressions of the ACE2 receptor required for the entry of SAR-CoV-2, unlike in older individuals who have higher risks of developing hypertension, diabetes, heart failure etc., which activates the production of more angiotensin II necessary for higher expression of ACE2. The gene discussed is AGT; the disease is heart failure.