In 2007, Dr. James Thompson (University of Wisconsin-Madison) co-discovered a groundbreaking way to create embryonic-like stem cells, using only simple, run-of-the-mill adult cells, with no embryos involved. His method involves the insertion of four genes into ordinary adult cells, which triggers the cells to revert to an embryonic-like state. In this state, the cells (known as iPS cells) can potentially be coaxed to become any cell type in the body – with enormous therapeutic potential to repair tissue damage from diseases like diabetes, heart disease, and Parkinson's.
This breakthrough is great news for several reasons: 1) it avoids the ethical controversy associated with embryo research, 2) it frees iPS cell researchers from research funding constraints imposed by the Bush administration and from potential legal issues in states with restrictive laws on embryo research, 3) the apparent simplicity with which iPS cells can be created has triggered renewed interest in stem cell research, especially in using stem cells for drug testing (see article for an explanation of how this works).
In the article, however, Dr. Thompson cautions that even this new method does NOT remove the need to continue research using stem cells derived from embryos. iPS cells are still being tested to see if they have all the properties of the embryonic type. The genetic manipulations required to create iPS cells also have some researchers concerned about using these cells in people's bodies.