TNF and diabetic kidney disease: Several studies have already established a link between TNF-α and renal fibrosis; for example, TNF-α acted as a central mediator of a broad range of biological activities in kidney tubules, including cell proliferation, cell death, differentiation, as well as induction of inflammation and immune modulation, indicating that TNF-α was involved in obstructive kidney disease and diabetic nephropathy fibrosis (16).