Type-2 diabetic nephropathy is one of the major long-term microvascular complications occurring in nearly 40% of diabetic patients in Japan. The purpose of this book is to review recent work on the genetic background, pathogenesis and treatment of this disorder and to provide the most up-to-date findings on these subjects in Japan. The pathogenesis of diabetic nephropathy includes both metabolic and / or hemodynamic factors, as well as renal hypertrophy. Hyperglycemia is necessary, but not sufficient, for its initiation and progression: The toxicity of persistent hyperglycemia results from glucose overutilization and multiple secondary effects. Moreover, diabetic nephropathy is generally considered to alter the chemical composition of the glomerular basement membrane and mesangium. At present, it is supposed that the increases in extracellular matrix accumulation due to TGF-beta activation might be related to the glomerular sclerosis in diabetic nephropathy. Although large numbers of candidate genes have been analyzed, those related to initiation and progression are still obscure in patients with type-2 diabetic nephropathy. Presenting clinical findings and issues related to laboratory analysis, this book will be of interest for nephrologists, diabetologists, pathologists, biochemists, general physicians and residents.