1. Transplantation Therapy Section, National Cancer Institute, Bethesda, Maryland, USA
2. Otsuka America Pharmaceutical Company, Rockville, Maryland, USA
3. Daiichi Pharmaceutical Company, LTD, Molecular Biology Research Laboratory, Tokyo, Japan
4. Immune Cell Biology Program, Naval Medical Research Institute, Bethesda, Maryland, USA
5. Holland Laboratories, Molecular Biology Laboratory, American Red Cross, Rockville, Maryland, USA