First, we expressed a construct encoding the GABAA subunit GABRG2 tagged with GFP in patient-derived DMG tumour cells and subsequently xenografted these GABAAR subunit-tagged tumour cells to the mouse hippocampus, a region to which DMG frequently spreads (Extended Data Fig. 3a), allowing engraftment for 8 weeks. The gene discussed is GABRG2; the disease is neoplasm.