TGFB1 and diabetic kidney disease: Thus, infiltrated macrophages in the inflamed kidney initiate production of profibrotic cytokines such as TGF-β, which play a key role in progressive renal fibrosis (Yang et al. 2007) In their studies, Park et al. (2000) and Kosugi et al. (2009) confirmed that ICAM-1, VCAM-1, and MCP-1 play a very important role in the pathogenesis of diabetic nephropathy by inducing inflammatory macrophage infiltration (Park et al. 2000), (Kosugi et al. 2009).