To investigate the synergistic activity of ONC201 in combination with RT against brain tumor cell lines, we treated a panel of human brain tumor cell lines including GBM cell lines SNB19, T98G and U251, and atypical teratoid rhabdoid tumor (ATRT) cell lines BT-12 and BT-16 with varying doses of TRAIL pathway inducer ONC201 and RT. This evidence concerns the gene TNFSF10 and glioblastoma.