Oligodendroglial tumours are a subtype of brain tumours accounting for about 10% of gliomas. Most of these tumours share a common genomic alteration – a genomic loss of both chromosomal arms 1p and 19q – but their prognosis remains highly heterogeneous. Thanks to a collaborative effort between the CIT team and the French national network POLA, the genetic material from a large cohort of patients could be deeply analysed at the molecular level. This work led to the identification of 3 previously unknown subtypes of oligodendroglial tumours with 1p/19q co-deletion which are characterized by distinct molecular profiles at the transcriptome, mirnome and methylome levels. One of these subtype shows a more aggressive profile associated with a high activation of MYC oncogenic pathway and a worse prognosis. This work has been recently published in the journal Nature Communications.