For example, previous published studies have shown that serum HE4 concentrations are significantly upregulated in ovarian cancer patients compared with patients with benign disease or healthy controls (Hamed et al., 2013), and combining HE4, CA125 and age as a diagnostic may optimize referral and diagnosis of patients with suspected ovarian cancer (Karlsen et al., 2015). This evidence concerns the gene WFDC2 and ovarian cancer.