Few complications of systemic diseases are better understood than diabetic nephropathy. In large part, progress in this area is due to Carl Erik Mogensen's steadfast preoccupation over more than three decades with the disorder's epidemiology, pathogenesis, pathophysiology, clinical diagnosis and evolving strategies of management. Though he sparked progress in each of these areas, he generously opens the forum of discussion to many expert contributors to this latest and most comprehensive edition of this exemplary textbook. In eliciting all relevant and up-to-date views, the reader, whether internist, pediatrician or specialist in endocrinology or nephrology, is assured a thorough review of the entire subject and in a format which is exceptionally well-written, well-illustrated and easy to read. Each of the prior editions have been an essential resource for my own work in this field and the 5th edition will no doubt continue to provide the information I and others will require to move forward in the years ahead. If only the other renal diseases were as masterfully synthesized, how much easier our task would be of achieving a comprehensive vision of all else in clinical nephrology. Barry M. Brenner, M.D., Samuel A. Levine Professor of Medicine, Harvard Medical School