In patients with recurrent glioblastoma (rGBM), the most aggressive form of primary brain tumors, administration of neoadjuvant anti–programmed cell death protein 1 (anti–PD-1) mAb blockade induces the activation and recruitment of intratumoral T lymphocytes into the tumor before surgery (7, 8). The gene discussed is PDCD1; the disease is glioblastoma.