1. Inserm, U773, team 11, Paris, F-75018, France, Université Denis Diderot-Paris 7, UMR S773 Paris, F-75018, France, CNRS, GDR Antibodies and therapeutic targeting 3260, Tours, F-37032, France, Centre de Recherche en Cancérologie de Nantes-Angers, Inserm, Université de Nantes, U892, Nantes, F-44000, France, and Department of Organic Chemistry, Vrije Universiteit Brussel, Pleinlaan 2, B-1050 Brussels, Belgium