[1] NCI, Genet Epidemiol Branch, Div Canc Epidemiol & Genet, NIH,DHHS, Rockville, MD 20852 USA
[2] NCI, Div Canc Epidemiol & Genet, NIH, DHHS, Bethesda, MD 20892 USA
[3] Informat Management Serv Inc, Rockville, MD USA
[4] NCI, Core Genotyping Facil, SAIC Frederick Inc, Frederick, MD 21701 USA