BASC-ing in the glow: bronchioalveolar stem cells get their place in the lung

Lung epithelial progenitor cell populations fulfill the needs of this complex facultative regenerative organ when exposed to insult and contribute to repair in either the airway or alveolar compartments. The presence of a cell that can populate both epithelia had been proposed previously but has remained elusive. In this issue, Salwig et al (2019) provide compelling, genetic evidence that supports a growing narrative—a rare population of bronchioalveolar stem cells (BASCs) that can contribute to both airway and alveolar epithelium in the distal murine lung.