 BHD syndrome is a rare genetic disorder characterized by skin lesions, lung cysts, and renal tumours. It is caused by mutations in the gene for folliculin, which regulates the activity of two proteins involved in lysosome formation and function. These proteins, TFEB and TFE3, are also important in tumour growth, and when they are inactivated, it can prevent the development of tumours in mouse models of BHD syndrome. Furthermore, inactivating either of these proteins in human BHD renal tumour cells can cause them to stop growing. This suggests that targeting these proteins could be a potential treatment option for patients with BHD syndrome. This article was offered by Chiara Di Malta, Angela Zampelli, Letizia Granieri, and others.