This study is the first to develop a recurrent, drug-resistant patient-derived tumor model (GBM10) in SD Rag2-Rag2tm1Hera knockout rats showing similar histological/pathological features to GBM found in humans, which is an important initial step toward addressing the need for a humanized intracranial PDX rat model of GBM. This evidence concerns the gene RAG2 and glioblastoma.