VIRAL IMPRINTS. “Less recognized are the contributions to our metagenome from viruses that establish chronic infection and retroviral elements that infest our chromosomes. How the dynamic nature of the interactions between this internal virome and the host imprints our immune system, and perhaps our physiology more generally, has been given little consideration.”
http://www.sciencedirect.com/science/article/pii/S0092867409007831