The Molecular Epidemiology Section (MES) brings together a unique skill set that combines epidemiological and laboratory research. We perform molecular epidemiology studies of prostate and breast cancer with a focus on health disparity and utilize translational research and systems biology approaches to identify exposures and related pathways that drive tumor development and progression. We seek to improve disease outcomes among African-Americans by gaining an understanding of their tumor biology, and how this knowledge can be harnessed to improve cancer prevention and care. Our research includes the large-scale analysis of gene expression, the evaluation of the tumor metabolome and proteome, and the discovery of biomarkers for disease development and progression. It also involves the analysis of genetic variations and their association with cancer using candidate gene approaches and the application of genome-wide association studies. Thus, our program applies innovative research strategies and is complementary and fully integrated into the transdisciplinary and collaborative research environment within the Laboratory of Human Carcinogenesis (LHC). This environment uses shared resources with a common Precision Medicine approach that integrates biology, population-based research, and clinical studies to advance prevention, early diagnosis, and clinical care of common and lethal cancer types.