Confocal imaging showed the presence of Cav-1 in the cytoplasm of lung epithelial cells, indicating that BC-derived Cav-1 could be delivered into lung epithelial cells from exosomes (Figure 1F). These results laid the foundation for further exploration of the effects and mechanisms of Cav-1 in BC-derived exosomes on the formation of lung PMN during BC metastasis. Here, CAV1 is linked to breast cancer.