Many of us are infected with a virus we’ll never clear. While we’re healthy, it’s nothing to worry about, but when our immune system is suppressed it could kill us. John Sinclair and Mark Wills, recently received a fifth consecutive five-year grant from the Medical Research Council (MRC), which focuses on understanding how Human Cytomegalovirus  is maintained as a latent infection in specialised cells of the immune system and how the immune system is prevented from eliminating the virus from the body.