Cancer has become the scourge of the 20th century. It was always part of the human condition, but until recently it was not a common cause of death as most people died from infectious diseases. Now that most of us will live long enough to be at risk of developing cancer, we need to learn as much about it as possible; this requires an understanding of molecular biology. John Cairns has made significant contributions to cancer research, molecular biology and virology. He believes that it is possible to explain what is known about cancer and molecular biology in terms that can be understood by readers with little or no scientific background. In this book, the author explores the revolution in public health, the origins and principles of molecular biology, and our emerging understanding of the causes of cancer. Finally, he discusses how these developments are likely to affect future generations. As Cairns points out, the last 200 years have altered our life expectations beyond recognition. Even in developing countries, people are starting to believe that everyone ought to be able to live well into old age and be protected from the major causes of premature death. This change in our expectations is one of the major benefits of technology and the biological sciences, but the resulting population explosion ultimately threatens everything we have gained by scientific progress.