As part of its Profiles in Science project, the National Library of Medicine has collaborated with the University of California, San Francisco Archives and Special Collections to digitize and make available over the World Wide Web a selection of the Harold Varmus Papers for use by educators and researchers.

For over three decades, Harold Varmus has advanced fundamental scientific knowledge at the intersection of virology, oncology, and genetics, both as a researcher and as a science administrator. With his long-time collaborator J. Michael Bishop, Varmus developed a new theory of the origin of cancer, which holds that the disease arises from mutations in certain of our own normal genes. These mutations are triggered by environmental carcinogens or by naturally occurring errors in the course of cell division and DNA replication. The genes that are susceptible to such mutations, Varmus and Bishop found, are closely related to genes in a number of cancer-causing viruses. The surprising discovery that cancer-causing genes, or oncogenes, originate in normal cells and are versions of normal cellular genes altered over time by accreted mutations suggested a common molecular mechanism for the many different types of cancer, explained why cancer is most often a disease of old age, and accounted for individual differences in the response to carcinogens. For 'their discovery of the ceelular origin of retroviral oncogenes,' Varmus and J. Michael Bishop shared the the 1989 Nobel Prize.