Susan Lea is Professor of Microbiology at University of Oxford. She is an outstanding structural biologist, working in the field of infection and immunity. Her research is focused on structures with specific medical significance in two important areas: the complement system and bacterial secretion systems. Professor Lea has investigated activation and regulation of the complement alternative pathway by both membrane bound and fluid phase proteins. Using novel structural approaches, she has provided insight into mechanisms underlying human diseases caused by genetic variation. Her group has made major advances in defining the architecture of bacterial secretion systems and her leadership skills are evidenced by her membership of multiple influential committees.