Immunostaining for neuronal subtypes at 21 dpi showed that >95% of glioma-converted TUJ1+ cells were positive for the excitatory neuron marker vesicular glutamate transporter 1 (vGLUT1) or vGLUT2, while <2% of the converted cells expressed GABA (gamma-aminobutyric acid) or GAD67 (67 kDa glutamic acid decarboxylase), which are markers for inhibitory neurons (Figure 2a; Supplementary Figure S5). This evidence concerns the gene GAD1 and central nervous system cancer.