PGR and breast cancer: By performing in silico analysis of available proteomic data [74]⁠, we found that lactadherin is underrepresented in BC cell lines, whereas it is highly enriched in EVs, being most enriched in EVs secreted by TNBC cells (such as MDA-MB-231), followed by EVs secreted by HER2- (ER + PR +) (such as MCF7 or T47D) and HER2 + cells in decreasing order (Additional file 1: Figure S6).