The 2021 World Health Organization (WHO) Classification defines glioblastoma (GBM) as a diffuse astrocytic glioma without IDH (Isocitrate dehydrogenase) and H3R gene mutations, with enhanced microvascular proliferation, necrosis, and specific alterations like gain of chromosome 7/chromosome 10 loss, EGFR (Epidermal Growth Factor Receptor) amplification, and/or TERT (Telomerase Reverse Transcriptase) mutations (1, 2). This evidence concerns the gene HRH3 and glioblastoma.