Maribeth V. Eiden, of the Laboratory of Cellular and Molecular Regulation at the National Institute of Mental Health, discusses her article “Koala Retroviruses: Evolution and Disease Dynamics,” which she wrote with Wenqin Xu for the 2015 Annual Review of Virology. Read their article at: http://www.annualreviews.org/doi/full/10.1146/annurev-virology-100114-055056