1. Department of Medical Biochemistry, University of Geneva, 1, rue Michel-Servet, CH-1211 Geneva-4, Switzerland, Laboratory of Molecular Therapeutics, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York 10021, Cerbios-Pharma S.A., 6917-Barbengo, Switzerland, and Department of Organic Chemistry, University of Geneva, 30, quai Ernest Ansermet, CH-1211 Geneva-4, Switzerland