Updated project metadata. MCF10A cells, and two isogenic mutant cell lines with known mutations in PIK3CA (E545 K and H1047R) were cultured in triplicate using culture medium depleted of extracellular vesicles. Cell culture supernatants were collected to study the extracellular vesicles (EVs) released by these cells. EVs were isolated from the samples by ultracentrifugation and their proteins digested. The resulting peptides were labeled with TMT and analyzed by mass spectrometry to identify differentially expressed proteins.