Stem cells are cells with the ability to develop into multiple cell types in the body. In theory, they can divide without limit to replace other cells as long as the person is living. When a stem cell divides, each new cell has the potential to either remain a stem cell or become another type of cell with a more specialized function, such as a muscle cell, a red blood cell or a brain cell.

More information about stem cells can be obtained from:

• National Institute of Health http://stemcells.nih.gov/

• The Burnham Institute http://www.burnham.org

• University of California, San Diego http://stemcells.ucsd.edu/