PIK3R1 and brain neoplasm: In brain tumours harbouring mutations in the PIK3R1 and PB1 genes, the presence of LE, IT and CTmvp regions negatively correlated with patient survival, likely reflecting the highly infiltrative nature of tumours bearing these histologies.48–50 Moreover, in patients harbouring mutations in the PDGFRA, KMT2C or EGFR genes, we observed a negative correlation between the presence of highly vascularised tumour regions and patient survival, again reflecting the more aggressive phenotype of this type of tumour.