After President Obama overturned Bush-era policy restricting federal funding of embryonic stem cell research in 2009, Nebraska Right to Life led a protest of the research outside the University of Nebraska regents' meeting. Nati Harnik/AP hide caption

itoggle caption Nati Harnik/AP

A scientist removes the nucleus from a human egg using a pipette. This is the first step to making personalized embryonic stem cells. Courtesy of OHSU Photos hide caption

itoggle caption Courtesy of OHSU Photos

The anthrax vaccine has been given to more than 1 million adults in the military. But no one knows how well it would work in children. Randy Davey/Reuters/Landov hide caption

itoggle caption Randy Davey/Reuters/Landov