Will tomorrow's medicines work for everyone?

Throughout much of the world, 'race' and 'ethnicity' are key determinants of health. For example, African Americans have, by some estimates, a twofold higher incidence of fatal heart attacks and a 10% higher incidence of cancer1,2 than European Americans, and South Asian– or Caribbean-born British are ∼3.5 times as likely to die as a direct result of diabetes than are British of European ancestry3. The health care that people receive also depends on 'race' and 'ethnicity'. African Americans are less likely to receive cancer-screening services and more likely to have late-stage cancer when diagnosed2 than European Americans. Health disparities such as these are one of the greatest social injustices in the developed world and one of the most important scientific and political challenges.