Book excerpt: The Human Genome Project completed sequencing the entire human genetic code in 2003, two years ahead of schedule. That brisk pace has characterized the private genomics industry as well, with prices for personal sequencing dropping from tens of thousands to only hundreds of dollars in less than a decade. Through this collection of articles, readers will recognize how DNA testing has opened new doors in medicine and science, as well as sparked new questions about medical ethics, human ancestry, and the self.