[1] Univ Cologne, Innere Med Klin 1, D-50924 Cologne, Germany
[2] Georgetown Univ Hosp, Lombardi Canc Ctr, Washington, DC 20007 USA
[3] Inst Canc Res, London SW3 6JB, England
[4] Univ Vita Salute, Ist Ricovero & Cura Carattere Sci IRCSS San Raffa, Milan, Italy
[5] Inst Pasteur, Montevideo, Uruguay
[6] Univ Ulm, Ulm, Germany
[7] Pinderfields Gen Hosp, Wakefield, England
[8] Univ Texas MD Anderson Canc Ctr, Dept Leukemia, Houston, TX 77030 USA
[9] Hosp Clin Barcelona, Barcelona, Spain
[10] Long Isl Jewish Med Ctr, Div Hematol Oncol, New Hyde Pk, NY 11042 USA
[11] Univ Calif San Diego, Rebecca & John Moores Canc Ctr, La Jolla, CA 92093 USA