CAV1 and breast cancer: A recent study indicates that caveolin-1 (Cav-1) present in exosomes originating from breast cancer cells can promote the establishment of PMN by inducing the upregulation of genes linked to PMN formation in lung epithelial cells and facilitating the M2 polarization of lung macrophages.41 In addition, Cav-1-containing exosomes inhibit the PTEN/CCL2/VEGF-A signaling pathway and promote pulmonary angiogenesis as well as M2 polarization of lung macrophages.42