Lucas et al. [34] suggested two subgroups arising from molecular testing: indolent / primarily childhood gliomas with biallelic NF1 inactivation of the NF1 gene (epigenetically “pilocytic astrocytoma, arising in the setting of NF1”), and aggressive / primarily adult gliomas with further genetic alterations such as CDKN2A homozygous deletion or ATRX mutation (epigenetically mostly high-grade astrocytoma with piloid features or subclasses of IDH-wildtype glioblastoma). The gene discussed is NF1; the disease is pilocytic astrocytoma.