CD81 and breast cancer: In detail, cancer cell lines of mammary origin, 8701-BC (from breast cancer), and the colon cancer cell lines Caco-2 and Colo 205 released EVs that were positive for both CD63 and CD81 (approximately 91 and 52%) and ALIX (approximately 49%), while healthy epithelium HB2 cells released approximately 88, 59 and 56% of EVs that were positive for CD81, CD63 and ALIX, respectively (Figure 3a and Figures S2–S6).