Protein-protein interactions play crucial roles in a number of biological processes, and, as such, their disruption is becoming an area of intense research. Despite the many challenges associated with the development of protein-protein interaction inhibitors, such as the large and relatively featureless interfacial areas involved, there has been considerable success in recent years. Importantly, through the existence of protein "hot spots", some of this success takes the form of small molecule inhibitors that have been identified from a variety of screening techniques.