Researchers from Harvard Medical School and the University of Toronto in Canada looked at 55 healthy, unrelated men and women, and they discovered 255 regions with relatively large gains or losses in their DNA. “We were extraordinarily surprised to see that some people have so much more or less DNA,” says Charles Lee, a geneticist and assistant professor at Harvard. “This is very exciting. It could explain differences in human nature, and help us identify people who are more prone to certain diseases.” “This discovery may help us to better understand the nature of humanity,” says Lee. To share their treasure, the Harvard-Toronto collaboration makes the details of their discovery available to the public in the Genome Variation Database ( A scientific report on the findings also appears in the September 2004 issue of Nature Genetics.