1. L. Zhang, W. Zhou, B. Vogelstein, Howard Hughes Medical Institute, The Johns Hopkins University School of Medicine, Baltimore, MD 21231, USA.
2. V. E. Velculescu, Oncology Center and Program in Human Genetics and Molecular Biology, The Johns Hopkins University School of Medicine, Baltimore, MD 21231, USA.
3. S. E. Kern, R. H. Hruban, S. R. Hamilton, Department of Pathology and Oncology Center, The Johns Hopkins University School of Medicine, Baltimore, MD 21231, USA.
4. K. W. Kinzler, Oncology Center, The Johns Hopkins University School of Medicine, Baltimore, MD 21231, USA.