We discovered that approximately one fifth of people with the deadly brain tumour glioblastoma show age-related genetic changes in their blood cells called ‘clonal hematopoiesis’, or CHIP. Patients with glioblastoma and CHIP had more aggressive tumours and worse outcomes, and our preliminary studies suggest that people with CHIP are more likely to get glioblastoma. We build on these findings here to address three key questions: does CHIP increase one’s risk of developing a brain tumour like glioblastoma? How might CHIP make glioblastoma more aggressive? And finally, how can we use CHIP to specifically target the signals that drive tumour development and progression with precision treatments? Our Canada-wide team is partnered with complementary international experts to answer these questions using cutting edge techniques in population genetics, single-cell genomics, and brain tumour modelling. Answering these questions could lead to novel biomarkers that enhance risk prediction and generate pre-clinical therapeutic strategies for validation in clinical trials. Our ultimate goal is to use this knowledge to improve outcomes for patients with glioblastoma.