GRM8 and central nervous system disorder: Consequently, we unearthed the GRM8 gene, encoding metabotropic glutamate receptor 8 (MGLUR8), a G-protein coupled glutamate receptor reported to significantly influence the risk of central nervous system (CNS) disease (28–30), and the AP1S2 gene, encoding AP-1 complex subunit sigma-2, a component of adaptor protein complex 1 and correlating with CNS disorder (31), as novel hallmarks linked to poor prognosis of Group 3 MB.