THBS1 and glioblastoma: The secretion of thrombospondin-1 (TSP-1), a synaptogenic factor, by tumour cells in functionally connected regions leads to elevated neuron–glioma interactions.146 Gabapentin, a U.S. Food and Drug Administration (FDA)-approved drug, effectively inhibits TSP-1 and results in reduced glioblastoma proliferation.146 Enhanced functional connectivity between glioblastoma and the normal brain corresponds to a decrease in patient survival and cognitive performance146 (Fig. 6).