IL4 and tuberculosis: Twenty-four studies were case-control studies.[9,11,12,14,21–24,26–29,32,33,35,37,38] The results disclosed that the serum IL-4 level of individuals with TB was greater than that of the healthy control group (SMD = 0.906, [95% CI, 0.272–1.540], I2 = 97.5%, P = .005); The 4 studies were cross-sectional studies.[31,34,39] The results were similar to the aforementioned findings, with increased serum IL-4 levels in diseased individuals (SMD = 0.527, [95% CI, 0.215–0.839], I2 = 41.4%, P = .001).