At present, the research on HE4 is mainly focused on ovarian cancer and endometrial cancer, the level of HE4 gene in ovarian serous carcinoma is significantly higher than that in other cancers, the levels of HE4 gene expression are moderate in transitional cell carcinoma, breast cancer, renal cell carcinoma and pancreatic cancer. The gene discussed is WFDC2; the disease is ovarian cancer.