IDH1 and neoplasm: We detected one astrocytoma, IDH-mutant case (SU-125) where the primary CNS WHO grade 3 tumor and paired CNS WHO grade 4 recurrence were classified as diffuse pediatric-type high-grade glioma, RTK1 subtype (calibrated scores 0.63514 and 0.91749, respectively), which is a subclass comprised of IDH-wildtype diffuse gliomas with malignant histomorphology that can occur in children and young adults [19].