Our human NF1-HGG line was derived from a malignant astrocytoma of a 42-year-old female Neurofibromatosis Type I patient and has full loss/inactivation of NF1, ATRX, TP53 and CDKN2A (Fig 1D–1F). Here, ATRX is linked to astrocytoma (excluding glioblastoma).