The goals of the Biostatistics and Data Coordinating Core are to provide biostatistical and data management services to support and enhance the quality of clinical research conducted by the project investigators. These services include study design, statistical analysis, biomathematical modeling expertise, interpretation of results, data quality assurance, and manuscript preparation. Core members, including biostatisticians and data management and computing professionals from the Division of Biostatistics and the Clinical Research Computing Unit with the Center for Clinical Epidemiology and Biostatistics (CCEB) at the University of Pennsylvania School of Medicine, will provide a broad range of collaborations for all projects. The aims of the BDCC are to: (1) Biostatistics: [a] Advise investigators on study design issues, including sample size and power considerations, for clinical protocols, animal studies and other laboratory research, [b] conduct statistical analyses of data from laboratory projects and clinical investigations to address specific hypotheses defined in the project-specific proposals, [c] assist with preparation for and writing of final reports, abstracts, manuscripts, and future research proposals, and [d] conduct exploratory analyses that may lead to generation of new hypotheses, (2) Data Coordination: [a] Implement a framework to facilitate data management and statistical analysis for projects by establishing interaction among biostatisticians, data management, computing and database personnel, and investigators, [b] design and implement procedures for tracking data flow through various study phases, [c] develop and implement procedures for case report form design and coding, data entry and validation, quality assurance, and reporting, and [d] design, test, implement, and maintain database structures and application programs to support Aims 2b and 2c.