1. From the Department of Pathology, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania (Kimambo, Vuhahula, Mwakigonja)
2. The Department of Pathology (Ljung, Ng), San Francisco Medical Center, San Francisco
3. Department of Epidemiology and Biostatistics (Zhang), San Francisco Medical Center, San Francisco
4. The Department of Medicine, Division of Hematology and Oncology (Zhang, Van Loon), San Francisco Medical Center, San Francisco
5. The Helen Diller Family Comprehensive Cancer Center (Zhang, Van Loon, Ng), San Francisco Medical Center, San Francisco
6. University of California, San Francisco Medical Center, San Francisco. Ng is now at the Department of Pathology, Memorial Sloan Kettering Cancer Center, New York, New York.