Human epididymis protein 4(HE4)is one of the four cDNAs expressed highly in human epididymis.HE4 is encoded by the WFDC2 gene,and has a stable 4-disulphide core,molecular weight is about 25 kDa,over expressed in slurry lung cancer,endometrial epithelial ovarian cancer,and uterine cancer.Currently HE4 is detected by enzyme-linked immune and chemical luminous particle immunoassay in clinic.HE4 is a novel type of tumor targeting index and biomarker in epithelial ovarian cancer.In 2009,the US Food and Drug Administration(FDA)approved that HE4 was used as a serum biomarker for the diagnosis of epithelial ovarian cancer.The studies have shown that,the diagnosis sensitivity of HE4,CA125 and Roma index in ovarian cancer patients was 65.63%、68.75%and 83.33%,respectively;the specificity was 100%、63.51%and 81.08%,respectively;and the positive predictive value was 100%、65.33%and 81.80%,respectively.Taken together,compared with the present biological indicators of CA125,HE4 is more specific and sensitive.Combination detection of HE4,CA125 and ROMA calculation index show a better predictive value for early epithelial ovarian cancer,especially for the serous ovarian cancer.Furthermore,the studies have shown that overexpression of HE4 can promote tumor growth,invasion,and metastasis in ovarian cancer.In addition,HE4 has a certain impact on other diseases such as liver cancer,chronic heart failure,and so on.