1. Departments of Clinical Pathology and Developmental Therapeutics, The University of Texas M.D. Anderson Hospital and Tumor Institute at Houston, Houston, Tex.
2. Department of Clinical Pathology, The University of Texas M.D. Anderson Hospital and Tumor Institute at Houston, Houston, Tex.
3. Department of Developmental Therapeutics, The University of Texas M.D. Anderson Hospital and Tumor Institute at Houston, Houston Tex.