WFDC2 and atypical endometrial hyperplasia: Immunohistochemical staining for HE4 was positive in 72 out of 84 (85.7%) endometrial cancer samples, 20 out of 30 (66.7%) cases of atypical endometrial hyperplasia, and 3 out of 18 (16.7%) healthy endometrial samples [61].