CTH and glioblastoma: To investigate whether CTH enabled GBM cells to cope with the oxidative stress we identified in GBM cells invading in hydrogels and patient specimens (Figure 4, B–E), we assessed ROS levels using the CellROX reagent, which measures hydroxyl radical and superoxide anion (40), in cultured GBM43 cells with or without CTHkd at varying oxygen levels.