BDNF and glioblastoma: The data showed that the protein level of BDNF was significantly elevated in GBM tissue compared with the normal group (Figure 1a and b, P < 0.0001), and the mRNA of BDNF in LN229 and U251 cells also was highly expressed compared with the NHAs cells (Figure 1c, P = 0.014; P = 0.0039).