BDNF and cancer: As shown in Figure 5(c), BDNF expression was also significantly correlated with the infiltration levels of Th2 cells in many cancers, including esophageal carcinoma (r = 0.17, p = 0.02), KICH (r = 0.46, p < 0.01), KIRC (r = 0.16, p < 0.01), brain lower-grade glioma (r = 0.14, p < 0.01), breast invasive carcinoma (r = 0.11, p < 0.01), liver hepatocellular carcinoma (r = 0.23, p < 0.01), lung adenocarcinoma (r = 0.15, p < 0.01), mesothelioma (r = 0.29, p < 0.01), and stomach adenocarcinoma (r = 0.19, p < 0.01).