1. Department of Pharmacology and Cancer Biology (D.K., J.D.N., C.-y.C., D.P.M.), North Carolina 27710;
2. Duke University Medical Center, and Department of Chemistry (T.P., D.B.), Duke University, Durham, North Carolina 27710;
3. Science and Engineering Group (C.E.C.), Research Triangle Institute, Research Triangle Park, North Carolina 27709;
4. SAS Institute (R.W., T.-M.C.), Cary, North Carolina 27513