GRM5 and central nervous system cancer: Indeed, the co-treatment of glioma cells with SC79 (AKT activator) and MPEP (mGluR5 antagonist) reverses the effect of the mGluR5 inhibition in glioma cells, indicating that AKT as a downstream of mGluR5 can regulate cell viability in hypoxia and normal conditions (75, 76).