Brain tumor immunotherapy: seeing the brain in the body

► Tumor immunotherapy shows promise but many challenges remain, for all tumor sites. ► Delivery barriers, tumor plasticity, and the need for tumor antigens apply to all. ► Insight into the complexity of immune regulation is needed for all. ► For brain, immune privilege and the blood-brain barrier receive great emphasis. ► Of equal value, brain shares principles, mediators and antigens with other sites.