VHL and glioblastoma: BRD4, BRD2, BRD3, and VHL were all expressed in U87, LN229, U251, and A172 (Fig. 2b), implying that BET and VHL proteins are widely expressed in GBM cells; The effect of treatment, with different GNE987 doses for 3 days, 5 days and 7 days, on the viability of GBM cell lines was assessed using CCK8.