At the annual meeting of the American Society for Cell Biology in San Diego, Christopher J. Murphy of the University of Wisconsin-Madison presented data showing that embryonic stem cells are more likely to keep their pluripotency when they are grown on a surface stamped with a pattern of tiny ridges. The effect was independent of the scale of the ridges, which ranged from nanometers to micrometers in width. Traditionally, cultured cells are grown on smooth glass or plastic surfaces.