But debate grows over whether use of human embryos is really necessary. However, as advancements in medical science leap toward providing better treatments, or even cures, new questions of morality and medical ethics abound.
Stem cells are the basis for every type of cell in the body.
Many scientists believe they hold the key to developing treatments for autoimmune diseases, Alzheimer's, Parkinson's and various forms of paralysis. It long has been believed that pluripotent cells are the most useful for research because they can be coaxed to form a variety of cells. The use of aborted human tissue has made stem-cell experiments morally controversial. But privately funded research of this kind is not prohibited. The legality of these guidelines, which encourage research that creates a market for human embryonic cells, will be decided after the conclusion of a review process established by HHS Secretary Tommy Thompson, whose recent congressional testimony did not tip the hat in either direction.