[1] Univ Perugia, Div Hematol & Clin Immunol, Dept Med, Perugia, Italy
[2] Stanford Univ, Dept Med, Div Blood & Marrow Transplantat, Stanford, CA 94305 USA
[3] Univ Aquila, Hematol Sect, Dept Life Hlth & Environm Sci, Laquila, Italy
[4] Univ Perugia, Biosci & Med Embryol Sect, Dept Expt Med, Perugia, Italy