MGMT and glioblastoma: Maintaining N3-methyl, but replacing C8-carboxamide with C8-imidazolyl (C8I) antitumour activity was observed in MGMT+ SNB19M and T989 GBM cells [Table 3] with 2-fold reduced potency compared to MGMT- SNB19V cells (IC50 ~33 μmol/L).