The angiopoietin/Tie-2 signaling axis plays an important role in vascular development during nephrogenesis, and a study of renal transplant recipients demonstrated that renal ischemia/reperfusion injury leads to rapid release of Ang-2, suggesting that Ang-2 could contribute to the development of ARDS in patients with AKI (12, 58, 59). This evidence concerns the gene ANGPT2 and acute respiratory distress syndrome.