1. Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA.
2. Institute for Transfusion Medicine, University Hospital Essen, University of Duisburg-Essen, Essen 45147, Germany.
3. Department of Medicine, University of Washington School of Medicine, Seattle, WA 98195, USA.
4. Department of Pathology, University of Washington School of Medicine, Seattle, WA 98195, USA.