CD4 and tuberculosis: The frequency of Mtb-specific CD4 T cells, producing IFN-γ, IL-2, and TNF-α, was similar among TBI-IMID (Figures 2A, B), TBI subjects (Figures 2C, D), and active-TB patients (Figures 2E, F) at T0 and T1 with the exception of a lower frequency of TB2-specific TNF-α+ CD4 T cells at T0 compared to T1 in TBI-IMID group (Figure 2B) and a higher frequency of TB1- and TB2-specific IL-2+ CD4 T cells at T0 compared to T1 in TBI group (Figures 2C, D).