CORE 3 - SUMMARY Core 3 will collaborate and consult with P01 Investigators on study design and data analysis to ensure the translational and mechanistic research will satisfy high scientific standards for statistical rigor. The requested funding will provide statistical support to the human studies and cell line experiments proposed in Projects 1-3, including collaboration with Core 1 on data management and computational components. In particular, the Biostatistics Core is a dedicated facility to provide ready and specialized access to: Aim 1: Statistical expertise for the design, planning and conduct of human studies and cell line experiments. Sample size considerations are critical in comparative studies of radiation modalities with dosimetry, imaging, circulating and tissue biomarkers. Aim 2: Statistical expertise for data analysis, interpretation and reporting of human studies and cell line experiments. Analysis plans include (a) development and validation of risk prediction models (b) assessment of adding a biomarker based on model performance (c) mediation modeling to decompose causal relationships into direct and indirect effects of radiation-induced lymphopenia or DNA damage response on patient outcome. Aim 3: Database consultation with Core 1 on (a) forms design, including coding conventions and variable formats (b) database specifications, including formatting of output datasets (c) quality control and audit processes.