Five sites of the Breast Cancer Family Registry (San Francisco Bay Area, New York, Ontario, Philadelphia and Utah) were recently funded by the National Cancer Institute to study the influence of behavior, environment and diet on pubertal growth in girls aged 6 to 13 years. The Legacy Girls Study is a five-year study that will enroll 900 girls and their parent or guardian and contact them every 6 months. Half of the girls will come from families with breast cancer, and the other half will come from families without breast cancer. We hope that you will join this novel and exciting research study with other girls across North America!