HGF and renal fibrosis: Studies using various renal injury models have demonstrated the ability of MSCs to repair kidney damage and attenuate renal fibrosis through modulation of the immune system40, the reduction in oxidative stress14,41, the secretion of soluble factors such as hepatocyte growth factor (HGF) and vascular endothelial growth factor (VEGF)17–19,21, and microvesicles20,41.