This book continues the story of a new field called molecular medi­ cine. The first edition appeared 10 years ago in a previous millennium. At that time cloning a gene was cutting edge research; now gene cloning is a high school science fair project. The complete sequencing of the human genome was finished last year; cloning a human is a likely (and very controversial) event for 2002. The tools of molecular medicine have become very powerful and automated; DNA on a chip and microarrays allow us to probe large parts of the genome and its function. The speed of sequencing DNA has increased about 100,0- fold over the decade since the first edition of this book was published. Following the great improvements in technology, DNA and molecular research have a rapidly deepening impact on human medicine. Molec­ ular therapies including DNA vaccines, antisense, and gene transplan­ tation are undergoing clinical trials.