EVs derived from ovarian cancer cells harbor specific biomarkerscritical for the diagnosis and monitoring of ovarian cancer. One of these biomarkers is human epididymisprotein 4 (HE4), a protein elevated in the blood of patients withovarian cancer. HE4 and other EV proteins,namely EpCAM, CD24, VCAN, and TNC, can distinguish high-grade serousovarian cancer (HGSOC) from noncancer cases with 89% sensitivity and93% specificity, effectively classifying patients into noncancer,early-stage HGSOC, and late-stage HGSOC groups. EV-encapsulated miRNAs may also be used as biomarkers forovarian cancer. Here, WFDC2 is linked to cancer.