A study conducted at MedUni Vienna and Vienna General Hospital within the framework of the Comprehensive Cancer Center (CCC) and in collaboration with the German Cancer Research Center in Heidelberg have conceptualised a potential biomarker for a particularly malignant subgroup of cerebellar ependymomas which has been published in leading journal Nero-Oncology. Ependymomas is the third commonest central nervous system tumours in children. The presence of the enzyme telomerase characterises a subgroup of cerebellar ependymomas and could provide information that allows a more accurate prognosis and hence also the choice of treatment. Telomerase was primarily reactivated in tumours that exhibit a particularly aggressive course which means that, despite surgical removal and subsequent radiotherapy and chemotherapy, the tumour recurred, making it a highly promising biomarker. But it needs to be validated in further studies.