CD4 and tuberculosis: For the variation in Th17 cells in the TB group, the percentage of Th17 cells in the CD4 lymphocytes was positively correlated with the percentage of Th1 (Pearson correlation: 0.466, p = 0.029) in the CD4 lymphocytes, Th2 (Pearson correlation: 0.785, p < 0.001) cells in CD4 lymphocytes, PD-1 in CD4 lymphocytes (Pearson correlation: 0.447, p = 0.037), PD-1 in Treg cells (Pearson correlation: 0.493, p = 0.037), PD-L1 in Th2 (Pearson correlation: 0.447, p = 0.048), and PD-L1 in Th17 (Pearson correlation: 0.540, p = 0.009) cells (Fig. 5).