During the late 1970s and 1980s, "cancer" underwent a remarkable transformation. In one short decade, what had long been a set of heterogeneous diseases marked by uncontrolled cell growth became a disease of our genes. How this happened and what it means is the story Joan Fujimura tells in a rare inside look at the way science works and knowledge is created. A dramatic study of a new species of scientific revolution, this book combines a detailed ethnography of scientific thought, an in-depth account of science practiced and produced, a history of one branch of science as it entered the limelight, and a view of the impact of new genetic technologies on science and society. The scientific enterprise that Fujimura unfolds for us is proto-oncogene cancer research--the study of those segments of DNA now thought to make normal cells cancerous. Within this framework, she describes the processes of knowledge construction as a social enterprise, an endless series of negotiations in which theories, material technologies, and practices are co-constructed, incorporated, and refashioned. Along the way, Fujimura addresses long-standing questions in the history and philosophy of science, culture theory, and sociology of science: How do scientists create "good" problems, experiments, and solutions? What are the cultural, institutional, and material technologies that have to be in place for new truths and new practices to succeed? Portraying the development of knowledge as a multidimensional process conducted through multiple cultures, institutions, actors, objects, and practices, this book disrupts divisions among sociology, history, anthropology, and the philosophy of science, technology, and medicine.