Dr Mayor has made outstanding contribution to the study of endocytosis in living cells. His work has greatly advanced the understanding of the endocytic pathway of lipid-anchored proteins. The concept of lipid rafts has emerged directly from Dr Mayor's work. His studies of endocytic processes have been based on the development of novel fluorescence methodologies which permit visualization of specialized domains in cell membranes. Dr Mayor's work represents a significant advance in the understanding of membrane-associated trafficking events in cells.