1. Cancer and Developmental Biology Laboratory, National Cancer Institute, National Institutes of Health, Frederick, MD;
2. Genomic Medicine Institute and
3. Lerner Research Institute, Cleveland Clinic, Cleveland, OH;
4. Mouse Cancer Genetics Program and
5. Mass Spectrometry Group, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, MD; and
6. Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA