The purpose of the Biostatistics Core is to provide professional expertise in biostatistics and bioinformatics for all Breast Cancer SPORE projects, investigators, and participants. Functions provided by this core include development of experimental designs, power analysis, and sample size estimation; data quality control statistical/bioinformatic analysis and interpretation of findings; and collaboration on presentation of results. To achieve these functions, the core director and core members are constantly available to investigators, and are in regular contact with project and core leaders. The primary objectives ofthe Biostatistics Core are: 1. To provide study design and review all laboratory, animal, and clinical studies including feasibility assessment, power analysis, and sample size estimation 2. To collaborate in project data analysis, interpretation of results, and the writing of final study reports and manuscripts 3. To work with the Pathology & Tissue Informatics Core and Imaging Core in the development of research project databases, to maintain data quality control and to ensure timely data capture 4. To develop and evaluate statistical/bioinformatic methods for experimental design and data analysis Biostatistics Core support is required in all Breast Cancer SPORE studies. Core personnel have worked and will continue to work closely with project leaders to ensure the core provides state-of-the-art statistical/bioinformatic support. RELEVANCE (See instructions): The relevance of the Biostatistics Core lies in our provision of services essential for the conduct of high-quality collaborative breast cancer research; sound statistical/bioinformatics inputs are critical throughout the lifespan of a research project, from conception to completion.