Background

“Stem cells” are utility and repair units of the body that serve a central function in the maintenance and regeneration of organs and tissues throughout life. Adult stem cells, derived mostly from bone marrow and umbilical cord blood, have been used in research since the 1960s, with applications focused primarily on treatments for cancer. Stem cells from human embryos were not isolated for the first time until 1998. Unlike their adult tissue counterparts, embryonic stem cells are “undifferentiated,” meaning these repair units of the human body have yet to be programmed to be specific to the brain, the skin, the heart, the lungs, or other bodily tissues. Research on embryonic stem cells is therefore considered by many scientists to be instrumental in developing a diverse supply of tissues to be used in the treatment of a variety of health problems including AIDS, diabetes, Alzheimer’s, Parkinson’s, spinal cord injuries, and heart disease (Johnson 2001).