Nigel Hooper is Professor of Biochemistry in the School of Biochemistry and Molecular Biology at the University of Leeds, UK. He received his Ph.D in 1984 from the University of Leeds with a thesis on the "Metabolism of Neuropeptides by Cell-surface Peptidases" which stimulated his interest in proteases and paved the way for much of his subsequent research. He currently co-leads the Proteolysis Research Group at Leeds and among other topics, continues to study the structure and function of several cell-surface proteases, with a particular interest in their mode of attachment to the membrane. He has published over 90 research papers, edited 4 books and co-authored the widely acclaimed undergraduate textbook Instant Notes Biochemistry. Uwe Lendeckel is a Reader at the Institute of Experimental Internal Medicine at the Otto-von-Guericke University of Magdeburg, Germany. After his study of pharmacology and toxicology he received his Ph.D in biochemistry in 1990 from the Ernst-Moritz-Arndt University of Greifswald. His thesis on the "expression of the pro-opiomelanocortin gene in rat Islets of Langerhans and other tissues" stimulated his interest in the neuro-immunological cross-talk and the regulatory roles of cell surface proteases therein. In 1989 he joined the ectopeptidase research group at the University of Magdeburg and since then continues to study regulation of expression and the function of T cell ectopeptidases in the normal and pathological immune response, with special focus on the membrane alanyl-aminopeptidase. He has published over 40 research papers.