[1] Univ Vermont, Larner Coll Med, Burlington, VT USA
[2] Univ Washington, Dept Biostat, Seattle, WA 98195 USA
[3] Univ Washington, Seattle, WA 98195 USA
[4] Univ N Carolina, Hematol & Oncol, Sch Med, Chapel Hill, NC 27515 USA
[5] Univ N Carolina, UNC Blood Res Ctr, Chapel Hill, NC 27515 USA
[6] NHLBI, Bldg 10, Bethesda, MD 20892 USA
[7] Univ N Carolina, Sch Med, Div Hematol, Chapel Hill, NC 27515 USA
[8] Univ Pittsburgh, Pittsburgh, PA USA
[9] Univ N Carolina, Dept Med, UNC Blood Reserach Ctr, Chapel Hill, NC 27515 USA
[10] Fred Hutchinson Canc Ctr, Seattle, WA USA