Dr Frisen reckons that they may offer several advantages over human embryonic stem cells which, although easier to manipulate, are a controversial source of new tissue because they are still mainly obtained from abortedfetuses.
Supporters of ongoing stem cell research -- which is controversial enough on its own because some existing stem cell lines were created from cells extracted from abortedfetuses -- say the field of study holds the promise of reversing or even curing many diseases.