FAS and disease arising from reactivation of latent virus: However, we also observed significant differences in expression patterns of Bcl-2, CD95, and Ki67 by CFP-10 and ESAT-6-specific CD3+CD8−IFN-γ+ cells (confirmed in a separate ICS assay to be CD4 T cells) in individuals with LTBI and patients with TB disease, thus suggesting these phenotypic markers are also differentially expressed by antigen-specific CD4 T cells in the context of latent infection and active disease in humans.