1. Charles River Laboratories, Pathology Associates, Research Triangle Park, North Carolina, USA
2. Experimental Pathology Laboratories Inc., Research Triangle Park, North Carolina, USA
3. Cellular and Molecular Pathology Branch, Division of the National Toxicologic Program, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, USA
4. Biostatistics and Computational Biology Branch, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, USA
5. Microarray Core, Toxicology and Pharmacology Branch, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, USA
6. Toxicology Branch, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, USA