The Framingham Heart Study is a longitudinal cohort study that began in 1948 and continues to this day. The objectives for the Framingham Heart Study are to significantly expand knowledge about the complex influences of genes and environment on development and progression of heart, lung, blood and sleep (HLBS) diseases and disorders, by utilizing the extensive array of new and existing information on genetics, behaviors, biomarkers, imaging techniques, and environmental factors. This objective is accomplished through re-examination of each of the three Framingham cohorts (Original, Offspring, Generation III) for measurement of complex phenotypes; through rapid distribution of DNA for extensive and focused genotyping; for rapid distribution of genetic and phenotypic measurements for use by investigators internal and external to the Framingham Study; and through analyses of the contribution of genes, new and established risk factors, and innovative biomarkers to the development and progression of subclinical and clinical disease.