Figure 5. A cartoon illustrating HSCs transdifferentiation to pneumonocytes for irradiated lung repair. The cartoon illustrates HSCs transdifferentiate into the lung cells under certain injury such as irradiation. Irradiation induced lung bronchial epithelial cell structure destruction, inflammatory cell infiltration and fibrous hyperplasia and impaired HSC residency in the lung. After HSCT, donor HSCs migrate into the injured lung, and some of them can be transdifferentiated to lung epithelial and endothelial cells to repair the injury imposed by irradiation.