When Olufunmilayo Olopade, M.D., now 48, was a medical resident in Chicago 13 years ago, she noticed the same disturbing trend among young Black female patients that she'd seen in her native Nigeria: aggressive breast cancer that wouldn't respond to treatment. Olopade watched helplessly as a 35-year-old cousin who had sought treatment in the States succumbed to it. Though research supported what she saw--White women are more likely to get breast cancer, but we tend to get it younger and die from it more frequently--the stats offered little explanation for the disparity. Olopade, a mother of three, became determined to solve the mystery. Today, as director of a cancer-research center at the University of Chicago, she has found an answer that will save lives.

Olopade suspected that the aggressive cancer had a genetic link, so she partnered with Nigerian doctors to study how genes affect the types of cancer that afflict women of African descent. Last spring the team discovered that a genetic mutation often causes tumors to start in different breast cells in Black women than in White women. These tumors are less likely to respond to traditional estrogen-based drugs. "Breast cancer isn't one single disease," Olopade says. "It affects women of different populations in different ways." She's pushing for doctors to rethink how they treat this form of aggressive cancer. And because the prognosis is usually better if cancer is caught early, she's calling for Black women to start screening at younger ages and for those with a family history of the disease to get genetic testing. In September Olopade received the MacArthur Foundation's "genius" award of $500,000 to further her work. "I want to translate research into real help--and better drugs--for women," she says.