In the animal models of hypoxia-induced pulmonary arterial hypertension [229,230,231,232], treatment with recombinant ACE2 or Ang(1-7) improved symptoms of pulmonary arterial hypertension (PAH) (lowered pulmonary arterial pressure, lung fibrosis, inflammation), however, there is a lack of evidence about the involvement of ACE2 in the models including both hypoxia and COPD. The gene discussed is ACE2; the disease is pulmonary arterial hypertension.