After a lot of frustration and too few successes, the cell therapy field has reached a new phase in its pursuit for better treatments for the deadly brain cancer glioblastoma multiforme (GBM). For decades, treatment approaches using surgery, chemotherapy, and radiation have sometimes helped to slow tumors’ growth, but the disease has almost always recurred and proved lethal. For that reason, over the last decade, O’Rourke and others began to explore cellular immunotherapies — similar to those developed at Penn Medicine and approved for certain blood cancers — as a potential better option for these brain tumors.