1. Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, CA;
2. Biomedical Engineering, School of Medicine and Division of Hematology, Oregon Health and Science University, Portland, OR;
3. Department of Surgery, University of California, San Francisco and San Francisco General Hospital, San Francisco, CA; and
4. Division of Hematology, Department of Medicine, University of California, San Diego, La Jolla, CA