Although there has been research on both adult stem cells and embryonic stem cells since the fifties, only adult stem-cell research has produced any cures—and lots of 'em. Adult stem cells have been used for decades to treat dozens of diseases, including Type 1 diabetes, liver disease, and spinal cord injuries. Currently, adult stem cells are used to treat more than eighty different diseases.
Harvard medical researcher Denise Faustman has used adult stem cells to cure diabetes in mice. Other cures from adult stem cells are being tested in hundreds of clinical trials. Adult stem-cell researchers in Switzerland take a few strands of hair from burn victims and use the follicular stem cells on the tips to create entire disks of new skin, a vast improvement on ugly skin grafts. Recently, patients with dam-aged livers have been helped by injections of bone marrow adult stem cells collected not directly from their marrow (an extremely painful procedure) but simply cultivated from their blood.
By contrast, the embryonic stem-cell researchers have produced nothing. They have treated nothing. They have not even begun one human clinical trial. They've successfully treated a few rodents, but they keep running into two problems: First, the cells tend to be rejected by the immune system. Second, they tend to cause malignancies called teratomas—meaning "monster tumors."
-Godless by Ann Coulter pg 125