All human embryonic stem cell lines approved for use in federally funded research are contaminated with a foreign molecule from mice that may make them risky for use in medical therapies, according to a study released Sunday.
Researchers at the University of California-San Diego and the Salk Institute for Biological Studies in San Diego report that if the stem cells are transplanted into people, the cells could provoke an immune system attack that would wipe out their ability to deliver cures for diseases such as Parkinson’s, Alzheimer’s and diabetes.