ABSTRACT The Biostatistics Core is responsible for providing statistical support to all projects. The Core will lead or assist in the development of all study databases and will lead their statistical analysis. The Core will perform a large variety of modeling tasks ranging from survival analyses using either relative risk (Cox) models or excess relative risk models. The Core will provide analysis of DNA methylation data including quality control, data normalization, software selection, and outcome analysis, and perform epigenome-wide association studies of quitting duration, and lung cancer risk. The Core will assist in the development of a CYP2A6 genetic score and in the application of this score to the analysis of lung cancer case control data. The Core will also provide analysis of ethnic and smoking differences, for targeted and untargeted adductomics data, Most statistical analysis will be performed using existing R or SAS procedures. In some cases, new statistical methodology may be developed if existing statistical procedures are inadequate for analysis.