The mTOR protein plays a central role in cell growth, proliferation and survival. Its activity varies according to the availability of nutrients and some growth factors, including hormones. This protein is implicated in several diseases, including cancer, where its activity frequently increases. To better understand its regulation, a team has identified the structure of the SEA complex — an interdependent set of proteins — responsible for controlling mTOR. The discovery of this structure allows a better understanding of how cells perceive nutrient levels to regulate their growth.