Abstract
Unraveling the fate specification of resident stem cells during lung regeneration is of clinical importance. It has been reported that c-kit(+) progenitor cells resident in the human lung regenerate epithelial lineages upon transplantation into injured mouse lung. Here we test the lineage potential of c-kit(+) cells by inducible genetic lineage tracing. We find that c-kit(+) cells do not contribute to lung epithelium during homeostasis and repair, and instead maintain a vascular endothelial cell fate. These findings call attention to the clinical application of c-kit(+) stem cells as lung epithelial progenitors for the treatment of pulmonary disease.