EV-associated tumor antigens such as HER2, EPCAM or Melan-A/MART-1 have been detected in the circulation and/or other body fluids in several types of cancer, including OvCa [78] and, accordingly, HER2- or EpCAM-specific antibodies are detectable in the sera of patients with HER2+ and EpCAM+ cancer, implementing a humoral immune response [79,80,81]. Here, EPCAM is linked to cancer.