Mean fluorescent intensity (MFI) of CD244/2B4 expression on antigen-responsive CD4+ T cells was also significantly higher in retreatment active TB patients as compared with latent infection individuals (p = 0.0006) and new active TB patients (p = 0.0029) (Fig. 1F and 2D). This evidence concerns the gene CD244 and disease arising from reactivation of latent virus.