Yolanda Roberson, who directs the Empowerment program, teaches a class at a Boys and Girls Club in the Bronx. The classes are funded by the state of New York. Robert Stolarik for NPR hide caption

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Jorje Mendez has lost more than 45 pounds through weightlifting and other lifestyle changes. Trainer Johnny Gonzales, right, helps prediabetic patients at the gym he set up at the Lake County Tribal Health Clinic in California. Farida Jhabvala Romero/KQED hide caption

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Dr. George Papanicolaou discovered that it was possible to detect cancer by inspecting cervical cells. The Pap smear, the cervical cancer screening test, is named after him. American Cancer Society/AP hide caption

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The U.S. Preventive Services Task Force recommends mammograms every other year, while the American Cancer Society endorses annual scans. Kari Lehr/Image Zoo/Corbis hide caption

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By measuring activity in different parts of the brain, neuroscientsts can get a sense of how some people will respond to treatments. John Lund/Getty Images hide caption

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Lucinda Schreiber for NPR

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