MGMT and glioblastoma: We have previously used T98G, a human GBM cell line known to constitutively express high endogenous levels of MGMT and harbor GOF TP53 mutation [20, 55] and generated stable short-hairpin (sh)RNA-mediated 90% knockdown of endogenous MGMT (T98/shRNA) and its counterpart transfected with empty vector (T98/EV) [56].