[1] Hosp Clin Barcelona, Dept Hematol, Barcelona, Spain
[2] Ctr Hosp Lens, Dept Hematol, Lens, France
[3] Ist Policlin San Matteo, Fdn IRCCS, Dept Hematol, Pavia, Italy
[4] Royal Hallamshire Hosp, Dept Hematol, Sheffield S10 2JF, S Yorkshire, England
[5] Univ Milan Niguarda, Dept Hematol, Milan, Italy
[6] Univ Florence, Dept Hematol, Florence, Italy
[7] Mayo Clin, Grad Sch Med, Div Hematol, Rochester, MN USA
[8] Hop St Vincent de Paul, Dept Hematol, Lille, France
[9] Ist Policlin San Matteo, Ctr Study Myelofibrosis, Clin Epidemiol Unit, Pavia, Italy