The quercetin–losartan (Q-L) hybrid retains the binding potential of losartan to the AT1R (Q-L IC50: 140 ± 10 nM; losartan IC50: 10.3 ± 1.1 nM), exhibits ROS inhibition and antioxidant capacity similar to native quercetin, modifies the cell-cycle distribution in GBM cells, and inhibits cancer cell proliferation and angiogenesis in primary GBM cultures [293]. This evidence concerns the gene AGTR1 and glioblastoma.