**Background of HE4 Antibody**
The HE4 (Human Epididymis Protein 4) antibody targets the HE4 protein, encoded by the *WFDC2* gene, initially identified in the epididymal epithelium. HE4 belongs to the whey acidic protein (WAP) family and functions as a protease inhibitor. Its clinical significance emerged when studies revealed overexpression in epithelial ovarian cancer (EOC), positioning it as a promising biomarker. Unlike CA125. a traditional ovarian cancer marker, HE4 demonstrates higher specificity for EOC, particularly in early-stage and non-mucinous subtypes, reducing false-positive rates in differential diagnosis.
HE4 antibodies are integral to diagnostic immunoassays (e.g., ELISA, chemiluminescence) that quantify serum HE4 levels, aiding in ovarian cancer detection, monitoring recurrence, and predicting prognosis. They are also used in immunohistochemistry (IHC) to localize HE4 expression in tissue samples. Additionally, HE4 antibodies have therapeutic potential, with research exploring their role in targeted drug delivery or immunotherapies.
Recent studies highlight HE4's involvement in tumor progression, influencing cell proliferation, adhesion, and metastasis, though mechanisms remain under investigation. Despite its primary association with ovarian cancer, HE4 is also elevated in endometrial, lung, and breast cancers, broadening its diagnostic utility. Commercial HE4 antibody-based tests, often combined with CA125. enhance diagnostic accuracy in algorithms like ROMA (Risk of Ovarian Malignancy Algorithm). Ongoing research aims to optimize HE4 antibody applications in personalized oncology and early cancer detection.