A 13-year-old girl gets an HPV vaccination from Judith Schaechter, a pediatrician at the University of Miami, in 2011. Joe Raedle/Getty Images hide caption

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Many arms, one robot: the business end of the da Vinci system is seen in this media handout image from the manufacturer. Mark Clifford/Courtesy of Intuitive Surgical, Inc. hide caption

itoggle caption Mark Clifford/Courtesy of Intuitive Surgical, Inc.

Actress Angelina Jolie at a news conference with Secretary of State John Kerry (in background) and other foreign ministers in London last month. They held a forum on how to reduce sexual violence against women in conflict zones — an issue she has often spoken about. Alastair Grant /PA Photos /Landov hide caption

itoggle caption Alastair Grant /PA Photos /Landov

A microscopic image of prostate cancer. Researchers have found new genetic markers that flag a person's susceptibility to the disease, as well as breast and ovarian cancer. Otis Brawley /National Cancer Institute hide caption

itoggle caption Otis Brawley /National Cancer Institute

A doctor checks for signs of skin cancer at a free cancer screening day in New York City. Spencer Platt/Getty Images hide caption

itoggle caption Spencer Platt/Getty Images

The U.S. ranks first in the world at stopping brain cancers, epidemiologists reported Monday. Here neurosurgeon Dr. Roger Hudgins and his assistant, Holly Zeller of Akron, Ohio, look at an MRI scan before performing surgery to remove a brain tumor. Mike Cardew/MCT /Landov hide caption

itoggle caption Mike Cardew/MCT /Landov

A simple switch of ingredients made a big difference in how mice responded to experimental cancer vaccines. Andrei Tchernov/iStockphoto.com hide caption

itoggle caption Andrei Tchernov/iStockphoto.com

STAR-certified physical therapist Jennifer Goyette works with cancer patients at South County Physical Therapy in Westborough, Mass. Courtesy of Jennifer Goyette hide caption

itoggle caption Courtesy of Jennifer Goyette