An increased EGFR expression, in turn, leads to an increased glutamate concentration in the TME (Fig. 2), which promotes glioma cells migration via phosphorylation of the COOH terminal (carboxyl-terminus) of GluN2B (glutamate (NMDA) receptor subunit epsilon-2), resulting in increased glutamate-NMDAR-signaling [12]. Here, GRIN2B is linked to central nervous system cancer.