In the post-COVID-19 group, the ACE activity level was not different according to sex (p = 0.322), age (p = 0.841), BMI (p = 0.144), months since patients’ discharge (p = 0.942), co-morbidities (T2DM p = 0.609; SAH p = 0.573; heart diseases p = 0.858), nor if patients still presented a respiratory dysfunction (p = 0.407). The gene discussed is ACE; the disease is heart disorder.