WFDC2 and ovarian cancer: Most previous HE4 studies have concentrated on the development and improvement of the serum detection assay, as well as the clinical application of the HE4 test for ovarian cancer diagnosis, prognosis, and triage of patients with pelvic masses [16–26] These studies have shown that serum HE4 levels, alone or in combination with additional tests such as CA125, provide superior specificity and sensitivity to CA125 alone, or with other biomarkers [27].