TGFB1 and diabetic kidney disease: In a model of diabetic nephropathy, urinary progenitor-secreted exosomes were found to reduce podocyte apoptosis by suppressing caspase-3 and promoting vascular regeneration, which may be related with the cytokines VEGF, TGF-β1, angiogenin and BMP-7 contained in urinary progenitor-derived exosomes [132].