Pleural VEGF levels in patients with TPE were significantly higher than those in patients with effusion due to CHF/CRF and transudate effusion (SMD = 1.5; 95% CI, 1.11 to 1.89; I2 = 72%; p < 0.0001) (Fig 8), whereas they were significantly lower than those in patients with MPE (SMD = -1.47; 95% CI, -2.06 to -0.89; I2 = 91%; p < 0.0001) (Fig 9) and lung cancer (SMD = -1.34; 95% CI, -2.05 to -0.64; I2 = 92%; p = 0.0002) (S5 Fig). Here, VEGFA is linked to lung cancer.