• There are three main types of stem cells: adult stem cells, embryonic stem cells and induced-pluripotent stem cells, or iPSCs.
  • In tissues like bone and muscle, adult stem cells can generate replacements for bone and muscle cells that are lost through injury, disease or normal wear and tear.  Adult stem cells are sometimes referred to as somatic stem cells.
  • Adult stem cells usually develop into the same type of cell as the tissue in which they reside.  Stem cells found in muscle tissue, for example, normally gives rise to new muscle cells.
  • Embryonic stem cells are “starter cells” that can be coaxed into becoming any of the specialized cells of the body, meaning they are “pluripotent.” Embryonic stem cells are derived from eggs fertilized in the laboratory, not in a woman’s body.
  • Induced-pluripotent stem cells are adult stem cells that have been genetically altered to behave like embryonic stem cells. At present, they serve a valuable role in research and drug testing.