ACE2 and acute respiratory distress syndrome: Moreover, our data demonstrate that ACE2 deficiency aggravates RSV-induced ALI and that administration of a soluble ACE2 recombinant protein ameliorates lung injury in vivo. Nevertheless, further studies assessing the potential therapeutic efficacy of recombinant human ACE2 protein are required using different animal models to verify the protective effects of ACE2 against RSV-induced lung injury.