CD8A and disease arising from reactivation of latent virus: Immunoregulatory molecules that have been associated with CD8 T cell dysfunction and immune exhaustion in chronic viral infections, including CD160, programmed death receptor 1 (PD-1), and 2B4 [36], have been reported to be expressed at low levels on CFP-10 and ESAT-6-specific CD8 T cells, both in the setting of latent infection and active TB disease [32].