CCL2 and breast cancer: Similar results were observed in our cell models, we have found that the high expression level of Cav-1 decreased the expression of PTEN and increased the expression of CCL2 and VEGF-A, which indicated that the inhibition of the PTEN/CCL2/VEGF-A signaling pathway induced by Cav-1 in BC-derived exosomes may promote the M2 polarization of macrophages and facilitate the lung PMN formation.