Portrait of American geneticist Mary-Claire King (b.1946). After studying mathematics in Illinois, King turned to genetics. She is director of the Human Genome Diversity Project, an international project which is mapping the genetic diversity of human mitochondrial DNA in order to help conserve ancient human populations. King is also working to isolate the gene responsible for inherited breast cancer (which affects 1 in 200 cancer victims) and the gene for inherited deafness. She has unmasked genetic differences in how people with AIDS react to the HIV virus. Her genetic work has also helped to reunite lost families who were displaced during the 1970's civil unrest in Argentina.