Indeed, analysis of plasma samples (from a healthy subjects), treated ex vivo with recombinant renin, showed an increase of Ang I, Ang II, Ang (1–7) and Ang (1–5), but not Ang (1–9) [115,179,181], further suggesting both the ACE2 specific activity in producing Ang (1–9) and an activation of both arms of the RAS in ARDS patients. This evidence concerns the gene REN and acute respiratory distress syndrome.