If this means being able to grow therapeutic quantities of adult stem cells (which avoids the ethical issues involved in embryonic stem cell lines), it would be an enormous boon both for medicine and for space development. Up to now, there's been pretty much no commodity that can be obtained in space (or on celestial bodies) that cannot be obtained more cheaply somewhere on Earth. Even the rare-earth metals that are increasingly critical for high-tech electronics are still cheaper from terrestrial sources (although politics can make getting them a hassle).
Stem cells have shown promise in a wide variety of therapies, including brain and spinal cord injuries, heart attack recovery, and dementia. But the sheer difficulty of getting them to grow in sufficient numbers has limited their usefulness to a few applications. If they can be grown in medically significant numbers in an orbiting lab, it might finally be the thing that kickstarts real space development of the sort G Harry Stine envisioned in his book The Third Industrial Revolution, but which foundered when the Space Shuttle failed to live up to its promise of cheap, routine access to space.