In podocytes of diabetic nephropathy, downregulated Gprc5a mediates podocyte foot process effacement, FSGS, and proteinuria by upregulating EGFR and TGF-β signaling pathways [47]; an upregulated EGFR signal can also promote the activation of the TGF-β signaling pathway [48]. This evidence concerns the gene TGFB1 and diabetic kidney disease.