CD4 and tuberculosis: The analysis of activated CD8+ T cells, producing any of the 3 cytokines (IFN-γ or IL-2 or TNF-α) showed similar results to CD4+ T cells, revealing a significant greater frequency of activated CD8+ T cells in both active TB (median 0.599%, range 0–4.55%) and LTBI patients (0.489%, 0–1.796%) compared to healthy controls (0%, range 0–0.249%, P < 0.0020 by Kruskal-Wallis test), but no difference was found between two groups of infected individuals (Figure 5(a)).