To further test whether BDNF–TrkB signalling regulates the number of neuron-to-glioma synaptic connections, we co-cultured glioma cells—with or without NTRK2 expression and expressing RFP-tagged PSD95—with neurons and quantified neuron-to-glioma synaptic puncta. The gene discussed is NTRK2; the disease is central nervous system cancer.