As illustrated in Figure 2B, during infection of IC-21 cells with MCMVΔm138, cell surface expression of ICOSL was maintained to levels similar to mock-infected cells, while the levels of CD84, a molecule targeted by the MCMV m154 protein (Strazic Geljic et al., 2020), used as a control, markedly decreased. Here, CD84 is linked to infection.