Interestingly, there appeared to be a trend toward differences in lineage specific phenotype by Mtb infection status, with CD4 T cells from individuals with active TB having generally lower Th1 cytokine production capacity (Figure 2) and a trend toward higher expression of CCR4 and lower expression of CXCR3 on Mtb-specific CD4 T cells, compared with indivdiuals with LTBI (Figures 4, 5). Here, CD4 is linked to tuberculosis.