A study of the environmental and genetic risk factors for breast cancer by the National Institute of Environmental Health Services and National Institute of Health, Department of Health and Human Services. The Sister Study is the only long-term study of women aged 35 to 74 whose sister had breast cancer. The study is to help understand how women’s genes and the things in their environment influence the risk for breast cancer. Visit Sister Study for more information or to participate. Revised January 23, 2007 | 
Courthouse 