GABRG2 and glioblastoma: The DA + AA cluster was mostly explained by the SH3GL2, DPP10, GABRG2 and GABRB2 genes, while the GBM cluster (including a few AA tumors) was characterized by the VEGFA, POSTN, CHI3L1 and SHOX2, among other genes (Fig. 3A, B).