IDH1 and glioblastoma: Adult and pediatric glioblastoma are resistant to treatment and invariably lethal.1 The current standard of care for these tumors involves surgery, radiation, chemotherapy,1 and/or tumor treating fields.2 Many promising clinical trials investigating the use of immunotherapies,3 laser interstitial therapy,4 novel biological agents, and targeted therapies such as IDH1 and BRAF inhibitors5,6 are underway and have the potential to improve survival in specific subpopulations.