Supplementary Material The following centers transplanted patients included in this study: Hospital Universitario La Fe, Valencia, Spain (G. Sanz); CHU Timone Enfants, Marseille, France (G. Michel); Hôpital Saint Louis, Paris, France (G. Socié) ; Hôtel Dieu, Paris, France (B. Rio); Hôpital de l'Archet 1, Nice, France (A. Sirvent); Hôpital Jean Bernard, Poitiers, France (M. Renaud); Nino Jesus Children’s Hospital, Madrid, Spain (L. Madero); Hôtel Dieu, Nantes, France (M. Mothy); Hospital Universitari Germans Trias I Pujol, Barcelona, Spain (J. M. Ribera); Hospital Reina Sofia, Córdoba, Spain (A. Torres); Hôpital Robert Debré, Paris, France (A. Baruchel); Hospital Infantil “La Fe”, Valencia, Spain (V. Castel); Leiden University Medical Center, Leiden, The Netherlands (M. Egeler); Institut Paoli Calmettes, Marseille, France (D. Blaise); CHU Bordeaux, Hôpital Haut-Lévêque, Bordeaux, France (N. Milpied); Ospedale Regina Margherita, Torino, Italy (F. Fagioli), Hôpital d'Enfants, Vandoeuvre, France (P. Bordigoni) ; Cliniques Universitaires St-Luc, Brussels, Belgium (B. Brichard); Royal Children’s Hospital, Melbourne, Australia (K. Tiedemann); Fairview University of Minnesota, Minneapolis, USA (J. Wagner); Hospital for Children and Adolescents, Helsinki, Finland (K. Vetteranta); University Hospital for Children (WKZ), Utrecht, The Netherlands (M. Bierings); Hôpital Albert Michallon, Grenoble, France (J.-Y. Cahn); Hôpital Claude Huriez, Lille, France (J.P. Jouet); IRCCS Policlinico San Matteo, Pavia, Italy (F. Locatelli); Hôpital Edouard Herriot, Lyon, France (M. Michallet); University of Liège, Liège, Belgium (Y. Beguin); Hospital Clínico, Salamanca Spain (S. Pérez); Sheffield Children’s Hospital, Sheffield, UK (A. Vora); Kantonsspital, Basel, Switzerland (A. Gratwohl); University Hospital, Zürich, Switzerland (U. Schanz); University Hospital, Leuven, Belgium (M. Renard); Ospedalo San Martino,Genova, Italy (A. Bacigalupo); Hôpital de la Pitié Salpetrière, Paris, France (J.-P. Vernant); Hospital Clínico Universitario, Valencia, Spain (C. Solano); Clinica di Oncoematologia Pediatrica, Padova, Italy (C. Messina); Sahlgrenska University Hospital, Goeteborg, Sweden (M. Brune); Ospedale di Careggi, Firenze, Italy (A. Bosi); Royal Hospital for Children, Bristol, United Kingdom (J. Cornish ); Heinrich Heine Universität, Düsseldorf, Germany (R. Haas); Institut Gustave Roussy, Paris, France (J.-H. Bourhis); Russian Children’s Hospital, Moscow, Russia (A. Maschan); The Children’s Hospital at Westmead, Sydney, Australia (P. Shaw); Hôpital Debrousse, Lyon, France (V. Mialou); CHU de Montpellier, Hôpital Lapeyronie, France (N. Fegueux); Hôpital Arnaud de Villeneuve, Montpellier, France (F. Bernard); CHU Augustin Morvan, Brest, France (C. Berthou); Hôpital de Pontchaillou, Rennes, France (C. Dauriac); University Tor Vergata, St. Eugenio Hospital, Rome, Italy (W. Arcese); Instituto di Clinica Pediatrica, Pisa, Italy (C. Favre); Children's Hospital Oakland, Oakland, USA (M. Walters); University Medical Center, Tucson, Arizona, USA (M. Graham); The Cleveland Clinic Foundation, Cleveland, Ohio, USA (C. McCracken); City of Hope Medical School, Duarte, USA (J. Rosenthal); The Institute of Medical Science, The University of Tokyo, Tokyo, Japan (T. Iseki); University Malaya Medical Centre, Kuala Lumpur, Malaysia (Chan Lee Lee). The following Cord Blood Banks and National Donor Registries have supplied cord blood units for patients included in this study: French Network of Cord Blood Banks ((France Greffe de Moelle Registry, Paris (F.Garnier, E. Marry), Besançon CBB (P. Hervé), Paris CBB (M. Benbunan), Bordeaux CBB (B. Dazey)); Centre de Tranfusio I Banc de Teixits, Barcelona, Spain (J. Garcia and M. Torrabadella); Milano CBB, Italy (P. Rebulla and L. Lecchi); José Carreras Stammzellbank, Düsseldorf, Germany (G. Kögler and P. Wernet); University of Liège Laboratory of Cellular Therapy, Belgium (E. Baudoux and Y. Beguin); London CBB, United Kingdom (C. Navarrete); De Leuvense Navelstrengbloedbank, Leuven, Belgium (M. Boogaerts); National Cord Blood Program, New York, USA (P. Rubinstein and C. Stevens); St-Louis CBB, USA (D. Regan); Leiden CBB, The Netherlands (W. Fibbe); Centro Regional de Transfusión Sanguínea, Málaga, Spain (C. Hernandez); Tokyo Metropolitan Red Cross Blood Center, Japan (T. Nagamura); and also University of Colorado CBB, Aurora, USA; Auscord, Sydney, Australia; Centro de Transfusion de Madrid, Madrid, Spain; Italian Bone Marrow Donor Registry (Firenze CBB, Torino CBB, Padova CBB, Lazio CBB (Tor Vergatta and La Sapienza, Roma), Pavia CBB); National Marrow Donor Program, Minneapolis, USA ; Cliniques St-Luc and Catholic University of Louvain, Brussels, Belgium; Paramus CBB, New Jersey, USA; Caitlin Raymond International Registry, Worcester, USA; German Red Cross Blood Service Baden-Wurttemberg-Hessen gGmbH, Mannheim, Germany; Valencia CBB, Valencia, Spain; Swiss CBB, Switzerland; Taiwan CBB, Taiwan; Royal Children's Hospital-Melbourne CBB, Melbourne, Australia; ARCCBB, Queensland CBB, Australia. Portland USA; Fakuoka CBB, Japan;