Stem cells are the body’s means of regeneration, and they naturally exist within many organs. They can be artificially derived from adult tissues (i.e. bone marrow) but also from embryos that are unused in in-vitro fertilization (IVF). Because many diseases are the result of cell death or improper cell programming, the use of stem cells as a tool to create healthy cells within the body has limitless possibilities.
Journal on World Affairs, UCLA 