Preface [Hot Topic: The Way Down from Single Genes and Proteins to Single Molecules (Guest Editors: Z. Foldes-Papp, J. Enderlein, J. Widengren and M. Kinjo)]

The collection of articles published under the motto “The way down from single genes and proteins to single molecules” is covering the results of groundbreaking developments of the recent years. They include single molecule detection yielding ultimate sensitivity and closely linked to the analysis of molecular noise by correlation spectroscopy. Several important examples from the field of nucleic acid as well as protein analysis as diagnostic tools are presented as well as the impact on the studies of single cells and biomembranes. The development of high sensitivity analysis at the single molecule level has in turn prompted the development of high-throughput protocols nowadays used in drug screening. In the attempt to make the vast and still growing knowledge of the human genome available for understanding the ultimate cause of disease and their therapy, these four special issues will fulfill a very important goal.