NF1 and glioma: The transplantation of these o-GSCs into the brainstems of 3-week-old NF1+/- mice yielded optic gliomas within 6 months, but not transplantation of o-GSCs into brainstems of immunocompromised athymic mice, emphasizing the need for NF1+/- local microenvironment in glioma formation (83).