Muscle wasting (also known as atrophy) occurs in many different diseases, for example in diabetes and cancer, and also when patients are immobilised following accidents or surgery. The loss of muscle that occurs in these cases is one of the major factors affecting recovery time, or indeed whether or not the patients do fully recover. In addition, as we get older, muscle wasting also occurs, which is one factor that can lead to loss of mobility. In order to develop drugs and therapies to help control muscle wasting, and to increase the quality of life for people affected by muscle wasting, we need a much better understanding of the changes which occur in muscle cells. In particular, we need to know what happens to the proteins which make up the muscle, and allow it to function properly. This application aims to work out the most important changes which occur in human muscle proteins during muscle wasting, which should allow us to develop better treatments for these conditions in the future.