Our group, along with other groups, has studied the role of RAS in local tissue injury,59,92,125–130 and showed that ACE-2 might be beneficial to attenuate lung injury.3,65,73 A future study by our group is planned to look at the effect of cycling of hypoxemia/normoxemia/hyperoxemia and the effect of ACE-2 in a small animal model of BPD. The gene discussed is ACE2; the disease is bronchopulmonary dysplasia.