The National Comprehensive Cancer Network (NCCN) updated guidelines to recommend cerebrospinal fluid (CSF)-based molecular tumor profiling for patients with high-grade glioma and glioblastoma when tissue biopsy isn’t feasible. The guideline update supports CSF sampling via standard lumbar puncture as an adjunctive diagnostic method, including where diagnosis and treatment depend on molecular markers such as H3K27-altered tumors. Belay Diagnostics said the change increases clinical utility for its CSF-capable assays, including its Summit 2.0 comprehensive genomic profiling panel and related CSF-based tests, which were analytically and clinically validated previously.