The control of growth.

The growth of a cell or tissue involves complex interactions between genes, metabolism, nutrition and hormones. Until recently, separate lines of investigation have concentrated in isolated sections of each of the many independent levels of growth control; the interactions within and between the diverse pathways that affect growth and size at the cellular, tissue and organismal level were little understood. However, new insights into the control of growth are now emerging in the context of signalling, ageing, evolution, cancer and nutrition. In particular, it is becoming clear that the insulin signaling network is a key player that integrates not only metabolism and the response to nutrition, but also the regulation of cell death, ageing and longevity, as well as the regulation of growth and body size.