WFDC2 and endometriosis: On the other hand, human epididymal protein 4 (HE4) is another widely used biomarker that is reported to provide better accuracy in differentiating malignant masses from benign ovarian adnexal masses, with a sensitivity and specificity of 90.5% and 87.9%, respectively [11], with significant effectiveness in advanced stages and conditions such as endometriosis.