Stem cells are the building blocks of the body. 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, cerebral strokes, and traumatic brain and spinal cord injuries. Therefore, stem cell research is as important for our understanding the physio- and pathology of the body, as it is for understanding of development and therapy, including for the nervous system. This book provides an overview and in-depth analysis of recent developments in stem cell research and therapy.