Like the masterless samurai for whom it is named, the protein Ronin chooses an independent path, maintaining embryonic stem cells in their undifferentiated state and playing essential roles in genesis of embryos and their development, said Baylor College of Medicine researchers who reported on this novel cellular regulator in the current issue of the journal Cell. Three proteins - Oct4, Sox2 and Nanog -- had previously been considered the "master" regulators of embryonic stem cells, but "Ronin could be as important as these three," said Dr. Thomas Zwaka, assistant professor in the Stem Cells and Regenerative Medicine (STaR) Center at...