Recent developments in experimental and computational chemistry, physics and life sciences have enabled a greater quantitative understanding of lipid asymmetry and its coupling to protein function. This Discussion explores the various facets of membrane asymmetry, bringing together experts in membrane physical chemistry, membrane biophysics, and membrane physiology. In this volume the topics covered include:Plasma membrane asymmetry and lipid homeostasisEngineering plasma membrane mimicsStructure and dynamics of asymmetric membranesProteins in asymmetric membranes