Affiliation: | 1. Division of Cancer Epidemiology and Genetics, National Cancer Institute, , Bethesda, Maryland 20892, U.S.A.;2. University of Maryland, , College Park, Maryland 20742, U.S.A.;3. Johns Hopkins Bloomberg School of Public Health, , Baltimore, Maryland 21205, U.S.A.;4. Dana Farber Cancer Institute and Harvard School of Public Health, , Boston, Massachusetts 02115, U.S.A. |