ACE2 and COVID-19: Similarly, if in that study we have pointed out that the increased activity of ACE (DD genotype) in conjugation with decreased activity of ACE2 (G allele) could be the underlining mechanism in hypertension susceptibility, here we hypothesize that the associated opposite effects on enzyme activity in the complementary genotype profile, that is, decreased ACE activity in conjunction with the increased ACE2 activity in patients with the protective genotype (II/A_), should be the protective physiological mechanism involved in COVID-19 outcome.