WNT4 and renal fibrosis: Stemming from previous evidence that the EMT process is critical for developing renal fibrosis and therefore promotes the progression of diabetic nephropathy to the end stages of kidney disease, changes in expression of EMT-related factors—Snail, Wnt4, and Notch2—in the kidneys of control and diabetic rats were examined in order to explore their potential role in the development and advancement of diabetic nephropathy.