The phenomenon of specific mutations shaping the histological appearance is well known for other brain tumors with mixed morphological phenotypes, such as atypical teratoid/rhabdoid tumors (AT/RT) arising in pleomorphic xanthoastrocytoma or ependymoma with loss of SMARCB1/INI1 expression being confined to the AT/RT component [8, 15]. This evidence concerns the gene SMARCB1 and ataxia telangiectasia.