Consistent with this, our patient-derived tumor specimens showed BDNF expression in astrocytes in the peritumoral region (Fig. 2d), whereas we saw similar levels of intracellular BDNF in all examined tumor-derived and non-tumor cell lines (BBM1, 361, astrocytes, and fibroblasts) (Additional file 2: Figure S5a). This evidence concerns the gene BDNF and neoplasm.