[1] Baylor Coll Med, Dept Pediat, Hematol Oncol Sect, Houston, TX 77030 USA
[2] Baylor Coll Med, Dept Med, Thrombosis Res Sect, Houston, TX 77030 USA
[3] McMaster Univ, Dept Pediat, Div Hematol Oncol, Hamilton, ON, Canada
[4] Univ Toronto, Dept Pediat, Div Hematol Oncol, Toronto, ON, Canada
[5] Univ Colorado, Dept Pediat, Sect Hematol Oncol Bone Marrow Transplantat, Denver, CO 80202 USA
[6] Univ Colorado, Dept Med, Div Hematol Oncol, Denver, CO 80202 USA
[7] Univ Alberta, Dept Pediat, Edmonton, AB, Canada
[8] Univ Penn, Dept Pediat, Div Hematol, Sch Med, Philadelphia, PA 19104 USA