Stem cells are the building blocks of the body and 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 autoimmune disorders, to neurological diseases and injuries, particularly neurodegenerative diseases, like Alzheimer's and Parkinson's disease and many others. This book provides 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.