作者单位:Fred Hutchinson Canc Res Ctr, Program Immunol, Clin Res Div, Seattle, WA 98104 USA[1]Univ Michigan Hosp, Dept Med, Div Hematol & Oncol, Ann Arbor, MI 48109 USA[2]VA Ann Arbor Healthcare Syst, Ann Arbor, MI USA[3]Univ Michigan, Dept Biostat, Ann Arbor, MI 48109 USA[4]