At the Telethon Institute of Genetics and Medicine (Tigem) in Pozzuoli, the team led by Andrea Ballabio has described in Nature* how the study of a rare genetic condition has provided the key to understanding a mechanism that leads to the formation of cysts and tumours in certain organs, in particular the kidneys. Supported by Fondazione Telethon, Fondazione AIRC for cancer research and Regione Campania, the study included the participation the European Institute of Oncology (IEO) and the Institute of Cell Biology at the University of Innsbruck