1. University of New Mexico School of Medicine, Departments of Pathology and Cell Biology, Albuquerque, NM 87131.
2. University of California, San Francisco, Department of Laboratory Medicine, Division of Molecular Cytometry, and Department of Medicine, San Francisco, CA 94143.
3. Osaka University, Institute for Molecular and Cellular Biology, Yamadaoka 1-3, Suita-shi, Osaka 565, Japan.
4. City of Hope Medical Center, Department of Pathology, Duarte, CA 91010.
5. University of Arizona Cancer Center, Department of Medicine, Tucson, AZ 85724.