Protein–protein interactions are one of most important classes of molecular targets in biotechnology. The ten chapters of this book provide an understanding of the key aspects in targeting PPIs with synthetic agents in a concise yet comprehensive manner. Experts in the field review the different strategies and chemical approaches that are used to target PPIs, discussing both established and novel methods. The in vitro tools used to assess the binding affinity and selectivity of PPI inhibitors are highlighted, and in silico tools used to aid the rational design of ligands are also reviewed. The book closes with a discussion of possible future directions to make this so-called ‘undruggable’ class of targets druggable. The book is a valuable source of information about targeting PPIs with synthetic agents, and provides a useful guide to the different chemical approaches that can be pursued and the in vitro analysis that can be used to assess potential PPI inhibitors.