When so-called senescent cells were removed from mice, they were healthier and lived longer than mice that still had the cells. Philippe Merle/AFP/Getty Images hide caption

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Scientists have the ability to use DNA from three adults to make one embryo. But should they? A. Dudzinski/Science Source hide caption

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Martin Shkreli was CEO of Turing Pharmaceuticals when the company boosted the price of a drug by 5,000 percent. He has since resigned. Paul Taggart/Bloomberg via Getty Images hide caption

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Alchemist Hennig Brand looks focused, if maybe a bit drained, in this 1795 painting by Joseph Wright. The painting depicts Brand's discovery of the chemical element phosphorus. Joseph Wright of Derby/Wikimedia hide caption

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Carolina "Maria" Hurtado in the now abandoned maternity ward of the Los Angeles County-USC Medical Center, where she was sterilized four decades ago. Renee Tajima-Peña hide caption

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Jamie Jones/Getty Images/Ikon Images

A pharmacist counts pain pills. In an effort to curb the abuse of Oxycontin, Vicodin and other opioid painkillers, some health plans in Massachusetts now limit a patient's initial prescription to a 15-day supply, and plan to halve that number in February. Gabe Souza/Getty Images hide caption

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Tim Kilroy runs a business from his home in Arlington, Mass. His insurance company quit covering the long-acting Ritalin that helps him manage his ADHD. Ellen Webber for NPR hide caption

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The routines that students learn at Dance for PD classes in Venice, Calif., can be quite challenging, instructors say. Courtesy of Joe Lambie and Laura Karlin hide caption

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