Nature, Published online: 14 October 2026; doi:10.1038/d41586-026-03085-0

Alveolar type 2 (AT2) cells are the stem cells of the lung’s air sacs and are responsible for maintaining alveolar structure and gas exchange. A study that tracked AT2 cells shows that, after injury to the airway, they can also migrate between lung compartments and become bronchiolar cells to help repair damaged airways.