ANGPT1 and pulmonary edema: Studies have shown that MSCs can reduce pulmonary vascular permeability and alleviate pulmonary edema [13, 31], partly through the secretion of growth factors such as angiopoietin-1 (Ang-1) [32], keratinocyte growth factor (KGF) [33], hepatocyte growth factor (HGF) [34], and vascular endothelial growth factor (VEGF) [35].