Mervyn Singer is Professor of Intensive Care Medicine at University College London and past Chair of the International Sepsis Forum. He co-led the ‘Sepsis-3’ redefinitions task force (Singer et al. JAMA 2016) that moved the emphasis of sepsis away from the bug and more towards a dysregulated host response triggered by the infection. He has researched and published widely on sepsis, infection and antibiotic use (and abuse) in journals such as NEJM, Lancet and JAMA, covering a broad range of basic mechanistic, translational and clinical research. He also provides advice on clinical management of sepsis to various national and international bodies.