Amid all the ranting and raving about research about the moral and ethical questions it raises, I have seen nothing published about the ultimate potential of stem cells. Ethical considerations aside (those can and will be discussed another day), consider what might be done someday. The attention has focused on potential benefits in treatment of a few diseases, with Alzheimer's and Parkinson's most frequently mentioned. That's great, but the real potential of stem cells is never mentioned. Stem cells are potentially able to produce a new and healthy duplicate of any cell, tissue, or organ in the human body. Hearts, yes, but also livers, skin, teeth, bone, blood vessels, nerves, arms, legs...all parts of the body. That means ANY damaged part can be regenerated and replaced. Need hip replacement because of arthritis or bone degeneration? Grow a new one. Blood vessels deteriorating and starting to leak? Grow new ones. It could well mean the average lifespan could go to--what?--200 years? 300? A fundamental change in the human race.