WFDC2 and hyperplasia: In 2011, Yang et al. [9] used an immunohistochemical method to detect the expression of HE4 in 31 cases of endometrial cancer, 19 cases of endometrial hyperplasia, and 20 cases of normal endometrial tissue, and the results showed that the positive expression rate of HE4 in the malignant group was significantly higher than that in the normal group and hyperplasia group and a statistically significant difference was observed between the groups.