[1] Brigham & Womens Hosp, Dept Med, Div Hematol, Boston, MA 02115 USA
[2] Dana Farber Canc Inst, Dept Canc Immunol & AIDS, Boston, MA 02115 USA
[3] Brigham & Womens Hosp, Dept Pathol, Boston, MA 02115 USA
[4] Emory Univ, Dept Pathol, Atlanta, GA 30322 USA
[5] Harvard Univ, Sch Med, Howard Hughes Med Inst, Boston, MA 02115 USA