This is because astrocytes secrete glutamate, which induces the mGluR1 signal in cancer cells through the WNT-5a/PRICKLE1/RE1 silent transcription factor REST axis, and then mGluR1 interacts with the epidermal growth factor receptor (EGFR) of lung cancer cells in a glutamate-dependent manner. The gene discussed is GRM1; the disease is cancer.