PDCD1 and glioblastoma: As the primary goal of the study was to evaluate dynamic [64Cu]-NOTA-GZP PET-derived metrics for immunotherapy response assessment in GBM, we solely evaluated combination oHSV and anti-PD1 ICB as a treatment strategy given its improved response rates in GBM models, which have relatively cold immune tumor microenvironments, to ensure a balance of both responders and non-responders 8,9.