MADISON, WI -  MARCH 10:  Irina Elcheva a employee of WiCell Research Institue, Inc. prepares stem cells for culture at the Wisconsin National Primate Research Center at University Wisconsin-Madison March 10, 2009 in Madison, Wisconsin. On March 9, 2009 President Barack Obama signed an order reversing the Bush administration's limits on human embryonic stem cell research. Getty Images logo Getty Images 9 months ago

MADISON, WI - MARCH 10: Irina Elcheva a employee of WiCell Research Institue, Inc. prepares stem cells for culture at the Wisconsin National Primate Research Center at University Wisconsin-Madison March 10, 2009 in Madison, Wisconsin. On March 9, 2009 President Barack Obama signed an order reversing the Bush administration's limits on human embryonic stem cell research.