PHYSIOLOGY OR MEDICINE
The cell cycle governs how a cell grows and makes copies of itself--and the understanding of this process achieved by this year's laureates is likely to be a major boon to cancer researchers. All the prizewinners uncovered molecules that help to control the cell cycle. In the early 1970s, working with yeast, Leland H. Hartwell of the Fred Hutchison Cancer Research Center in Seattle pinpointed more than 100 so-called CDC genes, or cell division cycle genes, including "start," which kicks off the cycle itself. In 1987 Paul M. Nurse of the Imperial Cancer Research Fund in London found the start gene in humans, now called CDK 1, or cyclin-dependent kinase 1. His work complemented the efforts of R. Timothy Hunt, also of the Imperial Cancer Research Fund, who discovered the first cyclin, a protein that binds to and in turn regulates the activity of CDK molecules.
This article was originally published with the title The Nobel Prizes for 2001.