John Sulston was director of the Sanger Centre in Cambridge from 1993 to 2000.There he led the British arm of the international team selected to map the entire human DNA sequence, a feat that was pulled off in record time by an extraordinary collaboration of scientists.Despite innumerable setbacks and challenges from outside competitors the ultimate success of the project can be attributed in large part to John Sulston's own determination, passion and scientific excellence. In this personal account he takes us behind the scenes of one of the largest international scientific operations ever undertaken.He is frank about the competition with Craig Venter and Celera Genomics, which threatened to undermine the international community's attempts to make the sequence freely available to everyone.He shares with us his excitement as the project unfolded. And as a pragmatist he reveals his hopes and concerns as to how the information unlocked by the Human Genome Project will affect people's lives in the future. The Common Thread is at once a compelling history of this most exciting of scientific breakthroughs and also an impassioned call for ethical responsibility in scientific research.As the boundaries between science and big business increasingly blur, and researchers race to patent medical discoveries, the international community needs to find a common protocol for the protection of the wider human interest.The Common Thread tells a story of our shared human heritage, offering hope for future research and a fresh outlook on our scientific understanding of ourselves.