The majority of the tumor biopsies (94%, 119/126) were classified with brain tumor methylation class families, which included diffuse glioma IDH-mutant (n = 31), glioblastoma IDH-wildtype (n = 45), meningioma (n = 38), low-grade ganglioglial/neuroepithelial tumor (n = 2) and diffuse pediatric-type high-grade glioma, H3-wildtype and IDH-wildtype (n = 3). The gene discussed is IDH1; the disease is neoplasm.