1. MRC Protein Phosphorylation and Ubiquitylation Unit, Sir James Black Centre, University of Dundee, Dundee DD1 5EH, U.K.
2. Dana Farber Cancer Institute, Harvard University, Boston, MA, U.S.A.
3. Worldwide Medicinal Chemistry, Pfizer Research, Cambridge, MA, U.S.A.
4. Inflammation and Immunology Research Unit, Pfizer Research, Cambridge, MA, U.S.A.