The application of MSCs in PAH treatment is based on the homing of MSCs to the site of injury, differentiation into endothelial cells, repair of injured endothelial cells, and concurrent secretion of paracrine factors, including various cytokines and mediators (such as VEGF) that promote endothelial cell repair and angiogenesis, thereby improving the symptoms of PAH [1, 23]. The gene discussed is VEGFA; the disease is pulmonary arterial hypertension.