Progression of chronic diseases in general and chronic kidney disease in particular has been traditionally viewed in the light of various contributors to development of glomerulosclerosis and tubulointerstitial scarring culminating in renal fibrosis. Indeed, this dogma prevailed for decades underscoring experimental attempts to halt fibrotic processes. Breakthrough investigations of the past few years on stem/progenitor cell involvement in organ regeneration caused a conceptual shift in tackling the mechanisms of nephrosclerosis. It has become clear that the rate of progression of chronic kidney disease is the net sum of the opposing trends: degenerative fibrotic processes and regenerative repair mechanisms. The latter part of this equation has been by and large ignored for years and only recently attracted investigative attention. This book revisits the problem of kidney disease by focusing on regenerative mechanisms in renal repair and on the ways these regenerative processes can become subverted by an intrinsic disease process eventuating in its progression. Cutting-edge investigations are summarized by the most experienced international team of experts.