Nathan R. Zaccai is a Research Associate at the Cambridge Institute for Medical Research, University of Cambridge. His current research focuses on the molecular and thermodynamic basis of the transport and presentation at cell surfaces of proteins involved in pathogen evasion and host immunity. Joseph Zaccai is Directeur de Recherche Emeritus at the Centre Nationale de la Recherche Scientifique (CNRS), Paris and Visiting Scientist at the Institut Laue-Langevin, France and Institut de Biologie Structurale, Grenoble. His current research interests include the exploration of the role of dynamics and physical chemical limits for life. He has many years of experience in teaching biophysics to biologists, medical students, and physicists. Igor N. Serdyuk (1939–2012) was Professor of Molecular Biology and Head of the Laboratory of Nucleoprotein Physics at the Institute of Protein Research, Russian Academy of Sciences, Moscow.