[1] Fred Hutchinson Canc Res Ctr, Program Immunol, Div Clin Res, Seattle, WA 98109 USA
[2] Univ Washington, Dept Med, Seattle, WA 98195 USA
[3] City Hope Natl Med Ctr, Div Pediat, Duarte, CA 90195 USA
[4] Univ Washington, Dept Immunol, Seattle, WA 98195 USA