In another recent study a reciprocal paracrine interaction between glioma stem cells (GSCs) and their progeny was attributed to activities of factors, such as neurosecretory protein, VGF, and brain-derived neurotrophic factor (BDNF) [21], each case involving a specific ligand-receptor pathway, as well as down-stream programs they activate. This evidence concerns the gene BDNF and central nervous system cancer.