1. Department of Molecular and Integrative Physiology (L.S.A., J.M.C., C.C.-S.), University of Michigan Medical School, Ann Arbor, Michigan 48109-0662
2. Department of Biological Chemistry (J.A.S.), University of Michigan Medical School, and Life Sciences Institute, University of Michigan, Ann Arbor, Michigan 48109-2216
3. Departments of Internal Medicine and Molecular and Integrative Physiology (S.A.R., M.G.M.), University of Michigan Medical School, Ann Arbor, Michigan 48109-5638
4. Department of Cancer Biology (R.I.K., J.A.M.), Dana-Farber Cancer Institute and Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115-6084