This issue of Neurosurgery Clinics, guest edited by Dr. Linda M. Liau, is dedicated to Glioblastoma: Molecular and Clinical Trials. This issue is one of four selected each year by the series consulting editors, Drs. Russell R. Lonser and Daniel K. Resnick. Topics will include—but are not limited to—Pathology & Molecular Markers, Cellular States & Genetic Diversity in Glioblastoma, Mismatch Repair in Glioblastoma Resistance, Genetic Susceptibility in Brain Cancer, Pediatric Gliomas: Molecular Landscape & Emerging Targets, Molecularly Targeted Clinical Trials, Novel Radiation Sensitizers, Immunotherapy Checkpoint Inhibitors, Brain Tumor Vaccines, CAR T Cells, Oncolytic Virotherapy, Targeting Cancer Stem Cells, Therapeutic Delivery to CNS, Theranostics: Dual Modality PET Tracers, and Neuroimaging & Novel Response Assessments.