PDCD1 and tuberculosis: Additionally, the frequencies of TIM-3 and LAG-3 expressing CD4+ T-cells (Figure 4A,G) and TIGIT, CTLA-4 and PD-1 expressing CD4+ and CD8+ T cells (Figure 4C–F,I,J, respectively) were significantly higher in HIV-TB co-infected individuals as compared to Mtb mono-infected ones (p < 0.05).