"De novo replication repair deficient glioblastoma, IDH-wildtype" is a distinct glioblastoma subtype in adults that may benefit from immune checkpoint blockade.

"data availability raw and processed dna methylation data from the de novo rrd glioblastoma cohort have been deposited at the ncbi gene expression omnibus (geo) under accession number gse239715. digitally scanned image files of representative h&e and immunostained sections from the de novo rrd glioblastomas are available at the following link: https://figshare com/projects/de_novo_replication_repair_deficient_glioblastoma_idh-wildtype/176784 . file 1 (pdf 3056 kb) supplementary file 2 (xlsx data availability raw and processed dna methylation data from the de novo rrd glioblastoma cohort have been deposited at the ncbi gene expression omnibus (geo) under accession number gse239715"

"Declarations Conflict of interestD.A.S. and A.P. are members of the editorial board of Acta Neuropathologica but were not involved in the handling or decision making for this manuscript. The remaining authors declare that they have no competing interests related to this study. Conflict of interest D.A.S. and A.P. are members of the editorial board of Acta Neuropathologica but were not involved in the handling or decision making for this manuscript. The remaining authors declare that they have no competing interests related to this study."

"Funding This study was supported by the Panattoni Family Foundation and the UCSF Glioblastoma Precision Medicine Program sponsored by the Sandler Foundation. D.A.S. was also supported by the Morgan Adams Foundation, the Yuvaan Tiwari Foundation, the Ross Family, the UCSF Department of Pathology Experimental Neuropathology Endowment Fund, the UCSF Program for Breakthrough Biomedical Research, and a Developmental Research Program Award from the UCSF Brain Tumor SPORE (P50 CA097257)."