An NF1 microdeletion in combination with an abnormal karyotype is an indicator of poor prognosis in AML; 7.6% of ovarian serous cystadenocarcinomas, 2.8% of lung squamous cell carcinomas, 3.3% of glioblastomas and 1.9% of phaeochromocytomas/paragangliomas harboured deletions [45, 82, 84]. This evidence concerns the gene NF1 and glioblastoma.