GNAQ and glioblastoma: Simultaneously, GA-T0 shows inverse agonism for the calcium level in GBM cells, suggesting Gαq-independent signaling activation of GPR17 in a dose- (Figure 2F) and time-dependent manner, with an EC50 of 19.64 μM and 47.33 μM for SNB19 and LN229, respectively (Figure 2G).