1. Genetics and Molecular Biology Curriculum, University of North Carolina, Chapel Hill, NC 27599, USA
2. Department of Genetics, University of North Carolina, Chapel Hill, NC 27599, USA
3. Division of Comparative Medicine, University of North Carolina, Chapel Hill, NC 27599, USA
4. Department of Microbiology and Immunology, University of North Carolina, Chapel Hill, NC 27599, USA
5. Department of Epidemiology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
6. Department of Pathology and Laboratory Medicine, University of North Carolina, Chapel Hill, NC 27599, USA
7. Texas Biomedical Research Institute, San Antonio, TX 78227, USA
8. Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC 27599, USA