1. Laboratory of Metabolism (N.H., T.K., S.K.), National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892
2. Department of Pathology (N.H., T.K.), Fukushima Medical University, Fukushima 960-1295, Japan
3. FACS Core Facility (B.J.T.), National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892