This agent has been shown to reverse resistance to TMZ by decreasing MGMT protein levels in glioma cells and animal models.21 However, in a clinical trial, the addition of O6‐BG had little therapeutic effect, and caused grade 4 hematological events in 48% of the patients, halting further attempts to use this concomitant therapy.22 The gene discussed is MGMT; the disease is glioma.