Another proof of principle in the bag for induced pluripotent stem (iPS) cells: "A little more than a year after [scientists] showed they could turn skin cells back into stem cells, they have pulsating proof that these 'induced' stem cells can indeed form the specialized cells that make up heart muscle. ... [the] research team showed that they were able to grow working heart-muscle cells (cardiomyocytes) from induced pluripotent stem cells, known as iPS cells. The heart cells were originally reprogrammed from human skin cells ... It's an encouraging result because it shows that those cells will be useful for research and may someday be useful in therapy. If you have a heart failure patient who is in dire straits - and there are never enough donor hearts for transplantation - we may be able to make heart cells from the patient's skin cells, and use them to repair heart muscle. That's pretty exciting ... It's also a few more discoveries away. The researchers used a virus to insert four transcription factors into the genes of the skin cell, reprogramming it back to an embryo-like state. Because the virus is taken up by the new cell, there is a possibility it eventually could cause cancer, so therapies from reprogrammed skin cells will likely have to wait until new methods are perfected. Still, the iPS cardiomyocytes should prove immediately useful for research."