Cystic fibrosis is a rare genetic disease which can cause very serious symptoms. In particular, patients suffer from chronic bacterial infections that can lead to respiratory failure. It is caused by mutations in the CFTR gene, which regulates water movement across the cell membrane. Consequently, mucus quality is altered, it is no longer capable of capturing undesirable bacteria and expelling them. Using a model reproducing a respiratory epithelium -- a protective tissue composed of a monolayer of cells -- scientists have discovered that a simple film of liquid is sufficient to restore the airways' seal and reduce the risk of bacterial infection.