Study: Genetics and environment distinctively shape the human immune cell epigenome. Specifically, while genetic factors primarily influence the gene bodies in memory immune cells, environmental factors tend to tweak the regulatory “switches”, enhancers, and promoters in naive immune cells. Background: Nature, Nurture, and Immune PlasticityTraditional wisdom held that environmental exposures determined an individual’s long-term health outcomes. Genetic Ancestry and Disease-Linked Epigenetic VariationAncestry and disease risks, genetic ancestry was found to influence immune epigenetic responses. Conclusions and Implications for Personalized MedicineThe present study provides evidence that nature and nurture are distinct architects of immune cell biology.