Interestingly however, our results imply that for viruses establishing latent infections in MHC I/II-positive cells where viral gene expression is extinguished but where viral proteins persist, a situation that could for example pertain to gamma-herpesviruses and their genome maintenance proteins, the latently-infected cell reservoir may remain visible to CD4+ T cells. Here, CD4 is linked to disease arising from reactivation of latent virus.