Stem cell therapy has the potential to rejuvenate Alzheimers-damaged brains, and has already helped cure some kinds of blindness. And there are two more reasons to be hopeful about stem cell treatments, announced this week.

Controlling Stem Cells
This morning Cell magazine published an intriguing article about a breakthrough made by several American scientists researching how stem cells get made. There is a small family of genes responsible for keeping stem cells "pluripotent," a state which allows the cell to turn into almost any other cell. Maintaining pluripotency is crucial for stem cell therapy.

Even more important is discovering how to restore pluripotency to cells that have already differentiated into a neurons or skin cells. Stem cells taken from blastocysts, or embryos, are pluripotent. But there is a limited supply of such cells for both practical and policy reasons (regulations against using embryos in experiments, for instance). So one of the gold rings of the stem cell research community is discovering how to make differentiated cells pluripotent agian.