High grade gliomas (HGG) are a group of tumours that can occur in any location in the central nervous system (CNS) and have a very poor prognosis with only around 20% of patients aged under 44 years alive at 5 years after their diagnosis. The tumours can occur in patients of all ages including very young children and infants. This project aims to look specifically at some of the rare and recently-discovered types of HGG occurring in patients aged 0 – 30 years old. We will gather tumour samples from our colleagues across the UK and the world to perform different experiments to understand more about these tumours. As these are rare and recently-discovered tumours, very little is currently known about them and therefore this project will try to fill in the gaps in our knowledge to help find particular weaknesses in these tumours that we can use to find better treatments and help to improve survival.