The pH inside our cells is constantly changing, but also carefully controlled within certain limits. Dynamic intracellular pH (pHi) is essential for normal cell behaviours, but when it becomes dysregulated, it can enable an array of diseases from cancer to Alzheimer’s. Dr Diane Barber from the University of California San Francisco has carried out extensive research into how normal pHi dynamics regulate cell behaviours and the impact that dysregulated pHi can have in different diseases.