Today, the pharma company GlaxoSmithKline (GSK) announced a five-year, $25-million-plus collaborative agreement with the Harvard Stem Cell Institute to develop new methods for screening drugs with stem cells.

"GSK believes stem cell science has great potential to aid the discovery of new medicines by improving the screening, identification, and development of new compounds," said Patrick Vallance, head of drug discovery at GSK, in a statement released by the company.

Big Pharma has mostly shied away from investing in stem-cell research. But drug screening, which some scientists say is likely to be one of the biggest near-term benefits of stem cells, is a growing area of interest.

Because stem cells can be differentiated into any type of cell in the body, they present an ideal source for screening. For example, scientists can determine how a candidate heart-disease drug affects heart cells and also look for potential side effects in liver or other cell types.

The time appears ripe for investing, because scientists can now use new reprogramming techniques to develop stem cells from patients with specific diseases. (While no one has yet reported this, word among stem-cell researchers is that it has been done.) That means they can make nerve cells from stem cells derived from an Alzheimer's patient and then examine how candidate Alzheimer's drugs affect the diseased cells.