The results showed that there was no statistical difference between the plasma IL-4 levels of patients with extrapulmonary TB and those of the healthy group (SMD = −0.505, [95% CI, −1.673 to 0.663], I2 = 87.5%, P = .397); 11 studies[40,42–48] provided data on plasma IL-4 levels in patients with pulmonary TB and healthy subjects. Here, IL4 is linked to pulmonary tuberculosis.