Normal cell function and metabolism is dependent on many thousand miniature energy-producing batteries known as mitochondria. Defective mitochondria are a hallmark of cancers, including brain tumours. The brain tumour research team at the University of Portsmouth has identified numerous, small defects (mutations) in the mitochondrial DNA of brain tumours, and are investigating how they contribute to altered cancer cell metabolism, tumour formation and sensitivity to anti-cancer drugs. This research will aid the development of new personalised therapies, improving patient outcomes. We have already identified functional mutations in sub-groups of GBM patients and are attempting to map drug response to some of our mitochondrially-acting novel and re-purposed therapeutics using protein modelling (in collaboration with our structural biology/X-ray crystallography colleagues at Portsmouth) and yeast studies (with colleagues in France). The Mitochondrial team works closely with the Therapeutics team in the area of metabolism and hypoxia in drug response. The concept of treating cancers as ‘one size fits all’ does not work and there is a great need to test models to bring personalised medicine closer to the clinic. We, along with our national and international collaborators, want to help bring advances to a place where biological information can help inform clinicians and their teams with therapeutic decisions for patients diagnosed with brain cancer to improve patient outcome.