Michel R. Popoff, D.V.M., Ph.D. (Microbiology) from the University of Paris (1985), Habilitation à Diriger des Recherches (HDR) from the University of Paris (1990), is the Head of the Anaerobic Bacteria and Toxins Unit and the Director of the National Reference Center for Anaerobic Bacteria and Botulism at Pasteur Institute, Paris, France. He is member of the French Veterinary Academy. His laboratory is focused on Clostridium toxins through genetic and biological activity analysis and has investigated the regulation of toxin synthesis in Clostridium botulinum and Clostridium tetani. In the recent years, we have analyzed the molecular mechanism of the actin depolymerizing C. sordellii lethal toxin and clostridial binary toxins, the pore-forming C. perfringens epsilon toxin, and the passage of botulinum neurotoxin through the intestinal barrier. He was co-editor of the 3° edition of the Sourcebook of Bacterial Protein Toxins Academic Press (2006).