1. G. S. Hotamisligil, P. Peraldi, A. Budavari, R. Ellis, B. M. Spiegelman, Department of Cellular and Molecular Biology, Dana-Farber Cancer Institute, and Department of Cell Biology, Harvard Medical School, 44 Binney Street, Boston, MA 02115, USA.
2. M. F. White, Joslin Diabetes Center and Department of Medicine, Harvard Medical School, Boston, MA 02215, USA.