The following keywords were used: [“endometrial cancer” OR “endometrial carcinoma” OR “endometrial tumor” OR “uterine cancer” OR “endometrial atypical hyperplasia” OR “endometrial hyperplasia” OR “atypical hyperplasia”] AND [“HE4” OR “human epididymis protein 4” OR “human epididymis secretory protein 4” OR” human epididymis-specific protein 4” OR “WFDC2”] AND [“immunohistochemistry” OR “expression” OR “overexpression”]. The gene discussed is WFDC2; the disease is endometrium neoplasm.