Mario Cortina Borja is professor of biostatistics at the UCL Great Ormond Street Institute of Child Health, and chairman of the editorial board of Significance magazine. He has a BSc and MSc from the Universidad Nacional Autónoma de México, and a PhD from the University of Bath. Before coming to UCL he was a lecturer at Instituto Tecnológico Autónomo de México, and consulting and teaching officer at the Department of Statistics, University of Oxford.