WFDC2 and ovarian cancer: Tumor proteins, such as CA125, Cancer Antigen 153 (CA153), Carbohydrate Antigen 19‐9 (CA19‐9), Carcinoembryonic Antigen (CEA), Ferritin (FERR), and Alpha‐Fetoprotein (AFP) and human epididymis protein 4 (HE4) for ovarian cancer and squamous cell carcinoma antigen (SCCA) for cervical cancer,[8] often fail to identify early‐stage cancers and differentiate cancer from benign diseases, leading to moderate sensitivity and unsatisfied specificity.