A phase 2 trial performed to evaluate the effectiveness as well as safety of niraparib with tumor treating fields (TTFields) in subjects with recurrent GBM.Measures safety and effectiveness of niraparib with addition to RT in treating recurrent GBM.A phase 0 “trigger” study of niraparib in newly diagnosed GBM and recurrent IDH1, IDH2, and ATRX mutant glioma. Here, IDH1 is linked to central nervous system cancer.