  Cancer research—and especially the hope and hype surrounding precision medicine—provides a focused lens through which to consider problems central to critical examination of the concepts and methods of the biomedical sciences. That is, cancer and the scientific study of cancer illustrate challenges facing disease classification, fuzzy borders between disease versus health, the problems with genetic essentialism, the ever-present reference class problem and ever promised solutions, as well as specific ways in which underdetermination of evidence in biomedicine shapes matters of justice in public health. Moreover, it provides a case study in how matters of evidence, disease status, and questions of values and justice are deeply intertwined.