Mighty Mice

The study Researchers at the biotech firm Novocell report the first successful use of human embryonic stem cells (HESCs) in treating a disease--diabetes--in mice. After generating HESCs from excess fertility-clinic embryos, the scientists cultured the cells for 12 days in a medium that directed them to become pancreatic cells. These were transplanted into mice whose own pancreatic cells had been deliberately destroyed, making them insulin-deficient. Within 45 days, new cells began producing fresh insulin.

What this means for us It's just a first step. In humans with Type 1 diabetes, the body destroys pancreatic cells, so the stem cells might be attacked the same way. The HESCs also produced tumors in the mice, making the method too dangerous to use yet.