Chapter 7: General Summary, Concluding Remarks and Future Directions

The adult lung has a complex structure that is composed of multiple specialized epithelial cell types, fibroblasts, two distinct smooth muscle populations (bronchial and vascular) and two parallel circulations (systemic and pulmonary), as well as a unique local immune system. This complexity of the lung structure is one of the major factors that has hampered the investigation of molecular and cellular mechanisms controlling lung cell development, behavior and function during both homeostasis and repair. However, the recent development of novel lineage-tracing tools and the discovery of informative cell markers have facilitated the identification of lung progenitor cell hierarchies…