Immunohistochemical micrographs of HE4 in different endometrial tissues (200x). The expression level of HE4 was higher in endometrial cancer than in endometrial atypical hyperplasia and normal endometrium. (a) Poorly; (b) moderately; and (c) highly differentiated adenocarcinoma. (d) Clear cell carcinoma and (E) uterine papillary serous carcinoma. (f) Severe; (g) moderate; and (h) mild atypical hyperplasia. (i) Secretory phase and (j) proliferative phase normal endometrium.