[1] Hosp Sick Children, Div Haematol & Oncol, 555 Univ Ave, Toronto, ON M5G 1X8, Canada
[2] Univ Toronto, Toronto, ON M5G 1X8, Canada
[3] Univ Cambridge, Dept Pathol, Tennis Court Rd, Cambridge CB2 1QP, England
[4] Addenbrookes Hosp, Dept Paediat Haematol & Oncol, Cambridge, England
[5] Univ Texas SW Med Ctr Dallas, Dept Pediat, Dept Mol Biol, Dallas, TX 75390 USA
[6] Univ Texas SW Med Ctr Dallas, Dept Internal Med, Dallas, TX 75390 USA
[7] Childrens Hlth, Gill Ctr Canc & Blood Disorders, Dallas, TX USA
[8] Addenbrookes Hosp, Dept Histopathol, Hills Rd, Cambridge, England
[9] Royal Victoria Infirm NHS Fdn Trust, Newcastle Upon Tyne, Tyne & Wear, England
[10] Yale Univ, Sch Med, New Haven, CT USA
[11] Univ Coll London Hosp NHS Fdn Trust, London, England
[12] Univ Minnesota, Div Pediat Epidemiol & Clin Res, Minneapolis, MN USA
[13] Univ Minnesota, Masonic Canc Ctr, Minneapolis, MN USA
[14] Emory Univ, Aflac Canc & Blood Disorders Ctr, Atlanta, GA 30322 USA
[15] Riley Hosp Children, Indianapolis, IN USA
[16] Univ Leeds, Inst Canc & Pathol, Leeds LS2 9JT, W Yorkshire, England
[17] Boston Childrens Hosp, Boston, MA USA
[18] Dana Farber Canc Inst, Boston, MA 02115 USA