CD8A and disease arising from reactivation of latent virus: Indeed, the response of naïve and memory conventional anti-MCMV CD8 T cells, but not the expansion of inflationary CD8 T cells during early and latent infection, requires a functional B7/CD28 activating co-stimulation axis (Arens et al., 2011) In contrast, the CD70/CD27 co-stimulation pathway promotes enhanced activation of MCMV-specific CD8 T cells for both conventional and inflationary responses, during both acute and persistent infection (Welten et al., 2013).