1 Hematology, IRCCS Azienda Ospedaliera Universitaria, San Martino-IST Istituto Nazionale per la Ricerca sul Cancro, Genova, Italy.
2 Hematology and Transplant Center, Ospedale Oncologico di Riferimento Regionale "Armando Businco", Azienda Ospedaliera Brotzu, Cagliari, Italy.
3 Hematology, Children's Center for Cancer and Blood Diseases, Children's Hospital Los Angeles, University of Southern California Keck School of Medicine, Los Angeles, California.