Ever since Crick and Watson discovered the structure of DNA, scientists have been trying to read the human genetic code locked in our chromosomes. When completed in the next century, the Human Genome Project will have determined every gene sequence in the human body, illuminating for scientists some of the outstanding problems in human biology: the origins of cancer, how embryos and foetuses develop, and the mechanisms of ageing. Written for both scientists and non-specialist readers, this book tells the story of the scientists involved in the project, the biomedical breakthroughs that led up to it, and how the information it generates may revolutionize our understanding of the human body and the treatment of disease.