Stem cells are the building blocks of the body. They can develop into any of the cells that make up our bodies. Stem cells carry a lot of hope for the treatment of a broad range of diseases and injuries, spanning from cancers, diabetes, genetic diseases, graft-versus-host disease, eye, heart and liver diseases, inflammatory and auto-immune disorders, to neurological diseases and injuries, particularly neurodegenerative diseases, like Alzheimer's and Parkinson's diseases, cerebral strokes, and traumatic brain and spinal cord injuries. Stem cell research is therefore as important for our understanding the physio- and pathology of the body, as for development and therapy, including for the nervous system. This book aims at providing an overview and in depth analysis of recent developments in stem cell research and therapy. It is composed of recently published review articles that went through a peer-review process.