“I think the importance is two-fold,” said Renee Reijo Pera, director of the Centre for Human Embryonic Stem Cell Research and Education at Stanford University, who was not involved in the study. “One is that if this can be extended to other species, it could be important for endangered species. The other is for women. There are a number of groups that have been working on this because it’s so important—and now this group [in Japan] has really broken through to show that what the field has been working on is quite valid.”