Although monozygosity of 22q has been reported in ~ 40% of RELA-fusion positive supratentorial ependymoma (ST-EPN-RELA) [52], the rarity of pathogenic somatic NF2 variants in the majority of intracranial ependymoma suggests a different tumor suppressor gene to be located on chromosome 22 [51, 53, 54]. This evidence concerns the gene NF2 and supratentorial ependymoma.