Lemme get this straight... glow-in-the-dark pigs will help stem cell research?

[Alex]

From a different article on the same story:

The scientists will use the transgenic pigs to study human disease. Because the pig's genetic material encodes a protein that shows up as green, it is easy to spot.

So if, for instance, some of its stem cells are injected into another animal, scientists can track how they develop without the need for a biopsy or invasive test.