GNRH1 and glioblastoma: Many previous studies had indicated that abnormal expression of GnRH and its receptor is found in various malignant tumors, not only in a reproductive system tumors but also in non-reproductive tissues, including breast cancer, ovarian, endometrial, prostate cancer, urinary bladder cancer, pancreatic cancer, and glioblastoma, suggesting that GnRH and its receptor might be used for targeted therapy with improved anti-tumor effects (10, 11, 28).