In addition, recently, we and other groups have reported that the angiopoietin (Ang) -Tie2 pathway mediates endotoxin-induced lung injury [3,12,13] and bronchopulmonary dysplasia (BPD) [14], a neonatal lung injury accompanied by an increase in lung vascular permeability [15,16]. This evidence concerns the gene ANG and bronchopulmonary dysplasia.