Overall, our findings indicate that lung EpCAM+ epithelial cells and CD31+ blood endothelial cells are the major sources of G-CSF in lung epithelial/stromal cells when stimulated with IL-17A, which plays a pivotal role in the development of Siglec-F+ neutrophils in PPE-induced emphysema mice. Here, PECAM1 is linked to pulmonary emphysema.