Department of Cancer Pharmacology, Millennium Pharmaceuticals Inc., Cambridge, MA, USA.|Department of Cancer Pharmacology, Millennium Pharmaceuticals Inc., Cambridge, MA, USA.|Department of Cancer Pharmacology, Millennium Pharmaceuticals Inc., Cambridge, MA, USA.|Department of Cancer Pharmacology, Millennium Pharmaceuticals Inc., Cambridge, MA, USA.|Department of Cancer Pharmacology, Millennium Pharmaceuticals Inc., Cambridge, MA, USA.