Former President Ronald Reagan died Saturday after a 10-year battle with Alzheimer's disease.

In recent years, Mrs. Reagan has promoted stem cell research, which many scientists believe could lead to cures for a number of diseases, including Alzheimer's.

The Bush administration severely restricted the research in 2001, limiting it to the 78 embryonic stem cell lines in existence at the time.

Critics of stem cell research cite religious and ethical grounds, as human embryos are destroyed when stem cells are removed from them for study.

Laura Bush's own father also died of Alzheimer's disease.