TSPO and glioblastoma: In 2015, Elkamhawy et al. reported a series ofquinazoline-urea-basedcompounds that demonstrated significant cell growth inhibitory potentialtoward proneural (GBM-1), mesenchymal (GBM-2), and classical (GBM-3)GBM.7089 was identified asthe most potent TSPO inhibitor that displayed substantial efficacyagainst the TMZ-resistant glioma cell line and also showed an acceptabletoxicity profile (Figure 23).