Around one in three people will at some time in their lives be diagnosed with cancer. For Western societies relishing health, wealth, and longevity, its continued prominence is one of the greatest challenges to science. Cancer is extraordinarily diverse in its causation, symptoms, likelihood of effective treatment - in some sense, every patient's cancer is unique, and that is part of the problem. Mel Greaves explains why the old paradigms of infectious diseases or genetic disorders have proved fruitless, and claims that by looking at cancer in its evolutionary context, we can begin to answer some of the big questions in cancer that concern us all. Drawing on both ancient and more modern evolutionary legacies, he shows how human development has changed the rules of evolutionary games, trapping us in a nature-nurture mismatch.