The purpose of this agreement with the NIEHS is to have funds (totaling $275,000) to set up a data coordinating center for data collection and processing from three Centers participating in the BCERC Epidemiology project. The Networking Coordinating Center at UCSF Bay Area has the responsibility of orchestrating the use of multiple pools of data from the epidemiologic studies. These funds are also needed to support programming and a data analyst to produce user friendly worksheets enabling visualization of trend and conclusions from the data. Coordinating Center: Data collection and processing from the three Centers participating in the epidemiology project. The Centers originally proposed limited hypotheses and plans for their local Centers, but under guidance from NCI and NIEHS, formed a collaborative project that increased the number of girls and power and scope of the study. The collection, processing, QC monitoring, and data inputting of the pooled data represents one of the most important activities of the Centers program and was not budgeted for in the individual awards nor was a data coordinating center budgeted for. Examination of the surveys, biomarker, and genomics information on the cohort of over 1100 girls from the three sites is already yielding unexpected findings that will likely generate novel hypotheses and insights into environmental influences on puberty and the risk for breast cancer. The Network Coordinating Center, under the direction of Dr Susan Stewart at the UCSF Bay Area Breast Cancer and the Environment Research Center (Director, Dr Robert Hiatt), has the responsibilities of orchestrating the use of multiple pools of data from the epidemiology studies, assisting in standardizing protocols, producing network-wide and public websites, and planning the multiple working groups, committee meetings, and national conferences. The collaborative project has made unexpected demands on the Epidemiology investigators in this Center. Dr Kushi and his staff have played a major role in coordinating analysis and efforts to produce the first wave of population studies on environmental influence on puberty and breast cancer risk. In addition, the team recruited beyond their proposed targets in order to assure optimal numbers of study participants for the combined study. Additional funds are need on an annual basis to support programming and a data analyst to produce user-friendly worksheets enabling visualization of trends and conclusions from the data.