In mechanistic studies using labeled TLX LBD and homogeneous time-resolved FRET (HTRF), xanthines promoted TLX homodimerization and heterodimerization with RXR as potential molecular mode-of-action, and treatment of human glioblastoma cells with xanthines altered expression of the TLX-regulated genes SIRT1, p21 and SLC1a1. Here, SLC1A1 is linked to glioblastoma.