To better understand how glioma-infiltrated brain slice-derived and activity-regulated secreted factors may affect microglial function, we performed an in vitro engulfment analysis which quantified microglial synaptic engulfment of excitatory (PSD95) or inhibitory (gephyrin) synapses in the tri-culture system, which enabled investigation of microglia-mediated engulfment of neuron-neuron synapses. Here, GPHN is linked to glioma.