1. Laboratory of Cell Regulation and Carcinogenesis (K.V.D., J.E.G.), Bethesda, Maryland 20892
2. Biometrics Research Branch (A.M.M., J.H.S.), EPN/8132, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland 20892
3. Department of Molecular Reproduction Development and Genetics (P.K.), Indian Institute of Science, Bangalore 560012, India
4. Comparative Medicine Branch (J.M.W.), National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892