 Murine cytomegalovius, MCMV, is a type of herpes virus that can cause disease in mice. It was found that MCMV can persist in certain types of cells called fibroblasts, which are responsible for making collagen and other connective tissue components. This persistent state of MCMV was found to be more active than its latent form, suggesting that it could be used as a model for studying viruses that persist in humans. This article was authored by Katazina M. Sytnik, Frank Krastanovich, Natasha Godek, and others.