[1] Univ Cambridge, Wellcome MRC Cambridge Stem Cell Inst, Cambridge CB2 0AW, England
[2] Univ Cambridge, Jeffrey Cheah Biomed Ctr, Dept Haematol, Cambridge CB2 0AW, England
[3] UCL Canc Inst, 72 Huntley St, London WC1E 6DD, England
[4] Lund Univ, Lund Stem Cell Ctr, Dept Lab Med, Div Mol Hematol, S-22184 Lund, Sweden
[5] Lund Univ, Dept Lab Med, Div Mol Med & Gene Therapy, S-22184 Lund, Sweden