1. National Center for Computational Toxicology, Office of Research and Development, United States Environmental Protection Agency, Research Triangle Park, North Carolina 27711
2. Department of Environmental Sciences and Engineering, University of North Carolina, Chapel Hill, North Carolina 27514
3. The Hamner Institutes for Health Sciences, Research Triangle Park, North Carolina 27709
4. CellzDirect/Invitrogen Corporation (a part of Life Technologies), Durham, North Carolina 27703